The hotly anticipated patch 2.2 went live yesterday without the vaulted voice chat feature activated, a select few realms set to get it earlier today...and they did, for about 30 minutes before disaster struck as realms were shut down and voice chat was taken offline in order to have a few more kinks worked out. The current plan is for it to be brought back online tomorrow, but don't get your hopes up.

While this was going on the CMs started going crazy releasing new information regarding it. Almost all of the class forums have had activity recently regarding changes they can expect in the 2.3 patch, which may not be as far off as some expect it to be as Eyonix suggests in this response:

Zul'Aman is done. We just need to get the raid dungeon on the public test realms, and make sure it sees extensive testing.

Don't worry, it won't require the same amount of testing as voice chat. I feel few truly understand what it took to impliment voice chat, and test it properly.

Warriors:

While arms/fury warriors aren't meant to be as good as protection warriors at tanking, we do plan to make an additional to Tactical Mastery that may help them out. This talent will grant greatly increased threat from Mortal Strike and Bloodthirst when in Defensive Stance.
source

It may also simplify things a bit to when we make Devastate combine the effects of Sunder Armor into it's effect and be affected by all talents and items that affect Sunder Armor. We plan to make this happen in 2.3.
source

Yes, we do plan to reduce the chance for Mace Specialization to occur in patch 2.3, but it will provide 7 rage instead of 6.
source

We also plan to have healing reduction effects affect all drain spells and abilities. As the example that most people bring up, Mortal Strike will affect Drain Life.
source

The Arms talent Weapon Mastery is going to be significantly changed. Instead of providing 50/100% chance to avoid Disarm effects, it is going to reduce the duration of Disarm effects by 25/50%. The reason for this is that having full immunity with this talent really took the idea of disarming out of the game and we want it to be more viable.
source

Druids:

We want to whack the cooldown [on Rebirth] from 30 minutes down to 20 minutes.
source

Hopefully the ability to cast Remove Curse in Moonkin form helps out at times, it's coming in 2.3. ;-)
source

We do want to increase the utility of the Druid of a bit, which can be a little rough in their specialized forms, so we are also making Cure Poison and Abolish Poison usable in Tree of Life Form.
source

I predict that the Intensity talent will now regen mana at 10%/20%/30% rate.
...
Hmmm... we will make it so.
source

We don't have any changes planned for Innervate, but we do plan to have Tranquility gain additional benefit from spell damage and healing bonuses.
source

Rogues:

Do you mean the amazing change to Shadowstep so that it can now be used at any time, not only while stealthed? In addition, after use of Shadowstep threat caused by the next Ambush, Garrote or Backstab will be reduced by 50%. The cooldown will however be increased to 40 seconds.

Also on the Subtlety front is a change to Dirty Deeds so that it will also be increasing damage of special attacks by 10/20% against targets that are below 35% health.

We're also taking a look at bumping up Hemorrhage a bit, but no details yet on what that may be.
source

Fleet Footed will now be a 15% speed increase instead of 8%.
source

I'm glad you asked, we actually have some changes coming in 2.3 for Deadly Throw. The speed at which it travels is being increased significantly, so it will reach your target much faster, and the snare duration is being increased slightly. One second longer if I remember correctly. It will, however, no longer have the ability to trigger Ruthlessness.

With that Ruthlessness mention I'll elaborate that we'll be changing it so that Ruthlessness will only affect melee finishing moves as a whole.
source

Regarding Blind:

Technically it's still a ranged attack that is part of the nature spell school, it just isn't a poison anymore.

(edit) Scratch that, we've updated it to be a ranged physical attack (also no longer counts as a poison).
source

Priests:

And here's a biggie:

Fear Ward will be available to all priests at level 20, but there are some changes in addition. Current plans are to reduce duration to 3 minutes, and increase the cooldown to 3 minutes.

To give the dwarves and draenei something else to even it out, they'll see a new ability called Chastise (also given at level 20) which will cause holy damage and incapacitate the target for 2 seconds.
source

In addition to what I didn't mention, Prayer of Healing, Circle of Healing and Holy Nova (healing effect) will gain additional benefit from damage and healing bonuses.

Circle of Healing is having a change to the base amount of healing though, and will be reduced but it will have the increase in the bonus it receives from bonus healing effects. So if you have more than 1338 healing, you'll see it heal for more. Less than that, you will see a reduction. Please keep in mind that these numbers could change on further testing but this is where we are as of right now for the patch.
source

For instance, Pain Suppression is getting changed a bit to have more utility beyond personal use. You'll be able to cast it on a friendly target and it will do a couple of things. First it's going to reduce the target's threat by 5%. and next it's going to reduce the damage that person takes by 40%. The cooldown is also going to be reduced to 2 minutes. The intent is to give it more utility while still making it viable for multiple targets. When you're trying to protect an AoEing mage in a raid, this could become a very useful tool.

Meditation is also going to geta bit of a bump up and it will increase to 10/20/30% mana regen as well.
source

On the survivability end, we're going to be having Power Word: Shield gain additional benefit from spell damage and healing bonuses. Base absorb values for ranks 10, 11 and 12 have been reduced though to go with that as a balancing factor for it. Unfortunately I don't have any concrete information on what the values will end up being right now.
source

Hunters:

For example, Serpent Sting, Immolation Trap and Explosive Trap are going to gain additional damage based on ranged attack power. I think everyone enjoys scaling.
source

Well it's not going to hit everything you want, but we are planning to change Wyvern Sting so that it will be instant cast.
source

Arcane Shot (ranks 6+) will dispel 1 magic effect in addition to the normal damage.
source

Shaman:

We have a few changes currently locked down for patch 2.3 that the elemental shaman should find beneficial. Being a level 70 elemental shaman myself, I'm particularly excited as currently I feel the class is in good shape, but in need of a few minor tweaks. I'd say the one I'm most pleased with (especially after seeing the results of change on an internal build) concerns lightning overload. When 2.3 launches it will have a 4/8/12/16/20% chance to occur, though the additional spell will cause half damage, still ending up being a noticeable increase to overall dps,.

Also, the additional spell will cause no threat whatsoever.

Though the following two changes have the potential to benefit all shaman, elemental and restoration shaman will likely benefit the most. The first change regards the mana spring totem. Previously it restored 12 mana every two seconds at maximum rank, for your entire party. As of patch 2.3 it will restore your groups mana by 20 every 2 seconds.

This equates to 50mana/5 for each member of your party without the talent points in restorative totems.

The second change impacts water shield. This spell will no longer cost any mana to cast (which also means the five-minute rule will not be affected) and the mana granted per globe has been substantially increased. Additionally, the spells duration has been shortened to one minute and at the end of its duration it now grants mana for any remaining globes.

Elemental Focus will now reduce the mana cost of the next two damage spells by 40%. Now before theorycrafting begins, this is actually a buff except in cases where your chance to land a critical strike with spells was extremely high.

Though I mentioned this in an enhancement shaman thread, for those who missed it, I'll reiterate -- Frostshock will no longer be subject to diminishing returns which I'm sure players will find useful, especially in pvp.

Lastly, we are making a change that will cause a reduction in dps, however, the elemental shamans overall dps will still be improving with the change that we're making to lightning overload. We're reducing the casting time of Lightning Bolt to 2.5 seconds (from 3 seconds), and chain lightning to 2.0 (from 2.5 seconds), causing benefit from spell damage to be reduced appropriately. The mana cost for these two spells are being lowered as well.

The lightning mastery talent's cast time will now be reduced by .1/.2/.3/.4/.5 seconds. So, casting time for the spells ends up being the same as before.

Keep in mind, some of what's listed above could change once the patch has received testing on the public test realms, and your feedback is always welcome.
source

An example of one helpful adjustment surrounds shamanistic rage, which will also reduces all damage taken by 30% for the duration of the ability (30 seconds), in addition to its current effect. Spirit Weapons will also reduce melee threat by a total of 30% rather than 15%. More improvements should be expected as well.
source

Yes, all shaman will be able to equip 2-handed axes and maces (proper training required of course), without having to spend a talent. In it's place, a seemingly solid replacement talent called elemental focus. Basically, what it offers is this -- after landing a melee critical strike, you'll enter a "focused state". The focused state will reduce the mana cost of your next shock spell by 60%.
source

You're welcome. No changes to those abilities, and while not the same, in patch 2.3 frost shock will no longer be subject to diminishing returns. This should prove useful.
source

Mages:

It may not matter for much longer though as we're changing Evocation in 2.3 to instead restore 15% of your total mana every 2 seconds, instead of being a Spirit-based mana regen increase.
source

It's called Ritual of Refreshment and will allow players to pick up their own stacks of food/water, similar to a Soulwell.
source

...in 2.3 we're planning a change for Ice Barrier to gain additional benefit from spell damage bonuses. However, the base absorb values of ranks 5 and 6 have been reduced.
source

What an amazing coincidence, it just so happens that [Arcane Meditation] is being increased to [10/20/30% mana regeneration] in patch [2.3].
source

Paladins:

Well along with a few other Ret changes we're putting the benefits of Improved Seal of the Crusader right into the base spell, and the talent will instead give the benefit of Sanctified Crusader. That of course means Sanctified Crusader needs something else, and it's being renamed Sanctified Seals, which will increase your change to critically hit will all spells and melee by 1/2/3% and reduces the chance your Seals can be dispelled by 33/66/100%.
source

We're pretty much focused on Retribution with 2.3, but some more general changes are being made like lowering the mana cost for Exorcism, Holy Wrath, and Hammer of Wrath.

Another Ret change (just to keep the momentum going) will be an increase to the duration of Vengeance to 30 seconds.
source

And poor Warlocks come in last:

The one thing I can give you for the next patch right now is that there is a change for Ritual of Souls which will significantly reduce the time to cast and complete it.
source

Professions:
Engineering:

And for your dedication, flying mounts for engineers only will be available in patch 2.3. There will be normal and epic versions of this mount for you to parade around and show how proud you are to have passed all the exams and call yourself an engineer.
source

I also heard this rumor that some Gan'arg Analyzers in Blade's Edge Mountains stumbled upon plans of a new Field Repair Bot and are hoarding them for their own purposes. Anybody plan to investigate this in patch 2.3?
...
I saw me one uh them new repair bots! I swears it! It wasn't tweren't not only repairin' items, it was hawkin' wares! I never didn't not did not didn't see nothing not like it never in my life!
source

Fishing:

Fishermen, and Fisherladies, will be able to track fishing nodes, similar to herbalism and mining. The ability will be learned from a journal you can find in fished-up crates.

There will also be a couple new types of fish found near Karazhan and Zul'Aman, with associated cooking recipes, one of which is a mana-regenerative soup on-par with Purified Draenic Water, but with a well-fed buff to boot.
source

Cooking:

You'll need cooking to be at a relatively high level to complete the cooking daily quests that are coming in 2.3, so I recommend leveling it up. ;-)
source

PvP:

We also are making it possible to buff in Battlegrounds the same as you do in the Arena. You'll be able to buff for free prior to the BG starting and also for a short period after being resurrected by a Spirit Guide. This is slated for the 2.3 patch along with more changes to AV. Hopefully, everyone will get into the PTR when it goes up and test out all of the changes and let us know how it feels.
source

We have some new daily quests targeting a random battleground each day. You'll want to keep an eye out for Alliance Brigadier Generals and Horde Warbringers near your faction's battlemasters in all major capitals. The battleground daily quests will reward gold, experience, and honor. You'll be able to begin these as soon as you're able to enter the battlegrounds themselves. So if it's a WSG day, and you're level 11, you can take the quest.
source