Next Warcraft Expansion: Cataclysm Confirmed and Detailed

The basics:

Two New Playable Races: Adventure as one of two new races--the cursed worgen with the Alliance or the resourceful goblins with the Horde.

Level Cap Increased to 85: Earn new abilities, tap into new talents, and progress through the path system, a new way for players to improve characters.

Classic Zones Remade: Familiar zones across the original continents of Kalimdor and the Eastern Kingdoms have been altered forever and updated with new content, from the devastated Badlands to the broken Barrens, which has been sundered in two.

New High-Level Zones: Explore newly opened parts of the world, including Uldum, Grim Batol, and the great Sunken City of Vashj'ir beneath the sea.

More Raid Content than Ever Before: Enjoy more high-level raid content than previous expansions, with optional more challenging versions of all encounters.

New Race and Class Combinations: Explore Azeroth as a gnome priest, blood elf warrior, or one of the other never-before-available race and class combinations.

Guild Advancement: Progress as a guild to earn guild levels and guild achievements.

New PvP Zone & Rated Battlegrounds: Take on PvP objectives and daily quests on Tol Barad Island, a new Wintergrasp-like zone, and wage war in all-new rated Battlegrounds.

Archaeology: Master a new secondary profession to unearth valuable artifacts and earn unique rewards.

Flying Mounts in Azeroth: Explore Kalimdor and the Eastern Kingdoms like never before.

Comments to follow at a later date.