Blizzard has confirmed that the newest and biggest content patch since Cataclysm's release is going live on servers this week - on Tuesday on US servers, and Wednesday on European servers. Alongside the official trailer, they have also posted a guide to all the content coming in the upcoming patch.» Source
The Hour of TwilightWorld of Warcraft Patch 4.3: Hour of Twilight nears, and with it, Deathwing’s reign of terror will finally come to an end. Featuring a new raid, unexplored dungeons, a legendary rogue quest line, the latest raid tier armor sets, major story developments, the Transmogrification and Void Storage features, and much more, Hour of Twilight has something for everyone.
Raid Finder - Enjoy our brand-new grouping feature that works much like the Dungeon Finder.
Transmogrification - Customize the appearance of your weapons and armor like never before..
Void Storage - Characters of all levels will be able to take advantage of this brand-new technology, which will open up 80 slots of long-term storage space.
Valor Changes - With patch 4.3, we'll be introducing some changes to the way Valor Points are obtained, as well as the items they can be exchanged for.
Fangs of the Father - Attention rogues! Play a central role in the fate of Azeroth by doing what you do best: manipulating key events from the shadows.
The All-New Darkmoon Faire - You’ll be dazzled. You’ll be amazed! You aren’t prepared for the Darkmoon Faire, ‘cause it’s like nothing you’ve seen before!
Raid Preview: Dragon Soul - Assist Thrall and the Dragon Aspects as they seek to bring an end to the Black Dragonflight once and for all.
Dungeons Preview: End Time - Deathwing roams the skies of Azeroth, wreaking havoc on the land and its people -- how can you stop him?
Dungeons Preview: Well of Eternity - Witness one of the most catastrophic events in Azeroth’s history: the War of the Ancients!
Dungeons Preview: Hour of Twilight - A most dangerous task awaits you: Escort Thrall and the Dragon Soul safely to Wyrmrest Temple, for the assault on Deathwing.
Links
Battle.Net Blog - Patch 4.3: Hour of Twilight
