Update - Added some more information from other interviews.
Patch 4.3 Interview with Greg Street (Ghostcrawler)
Below is a quick summary and the full thanks to Simca. Be sure to read it so that you don't miss anything! (Extra info via Joystiq, Eurogamer, TenTonHammer, and Tankspot)
- The new raid is called The Dragon Soul. It contains eight bosses, and boss 7 and 8 are both Deathwing.
- There will be a mount reward for killing Deathwing.
- Deathwing will only drop weapons.
- Heroic Deathwing will eventually be made easier after the top guilds kill it so that more people can experience it.
- Tier 13 will not be available at all from valor points.
- The new legendaries are two daggers (main hand and offhand) that are only usable by all three Rogue specs. Combat Rogues will be made to use these daggers as well without a DPS loss. The questline will revolve around the pure black dragon (from the egg in the Badlands) and features several Rogue-centric elements.
- Melee classes will be getting a buff that is only active in the new raid to help them compete with ranged classes.
New Five Man Heroics
- You will enter the new 5-mans and raid in Caverns of Time.
- The first new 5-man is called "Endtime" where Nozdormu will show players the future if Deathwing wins.
- The second new 5-man, "Well of Eternity" is a journey into the past, the War of the Ancients specifically, to help Thrall recover the Dragon Soul to use against Deathwing.
- The third new 5-man, called "Hour of Twilight", has players escorting Thrall in present day to Wyrmrest Temple, where the final battle against Deathwing will take place.
Looking for Raid
- Looking for Raid probably won't share a lockout with Normal and Heroic raids.
- Looking for Raid gear will be stronger than the new five man heroics, but weaker than normal raids.
- There will be raid melee buff across the board. The attack power buff will apply more to melee attack power than ranged attack power.
- Tank rotation changes that are related to survivability won't be in this expansion.
- Epic gems will drop in the new raid in Normal and Heroic only. Each player gets a geode when a boss is killed which has a small chance to contain an epic gem, most will have rare gems. It is rare enough to take all of 4.3 to replace all of your red rare quality gems with red epic gems.
- Firelands was nerfed so that players could see the content and continue progression instead of hitting a wall in heroic modes.
- "Quite a few" new profession recipes will be added.
- Northrend will require 2/3rd of the experience it does now, making leveling alts faster.
- Corrupted Ashbringer won't be available for transmogrification from any vendor.
- Old PvP armor will come back for transmogrification.
Originally Posted by Blizzard Entertainment