The next expansion is comfirmed to be the rumored Cataclysm. This bring new level cap, new classes (although old faction), new zones and bosses.
Goblins
Deathwing once again sought the services of the goblins, as slaves. Unable to refuse such an offer, the goblins were enslaved by him. A large group have resisted however. With their previous homes devastated by the cataclysm, they escaping to an island off the coast of The Barrens. As they strive to recover, they come across an Orc captured on an Alliance ship and rescue him. The Orc turns out to be none other than Thrall himself, and in return offers the Goblins a place within the Horde. These events are carried out in a quest line, allowing players to experience first-hand the reasons behind the Goblins' shift from neutrality.
Worgen
The cataclysm has cracked open the Greymane Wall, finally revealing what has happened to the kingdom of Gilneas and its citizens. With the Worgen curse taken hold, they have found a partial cure, allowing thme to retain their Human minds even when transformed. Venturing forth from Gilneas and seeking help from the Alliance, they have decided to join them, to combat the new threats of Cataclysm.
Flying in Azeroth
Part of the redesign of the Eastern Kingdoms and Kalimdor is the introduction of flying to the two continents, allowing access to many new areas and quicker travelling across the large continents.
Classic Dungeon Revamp
Redesigning Onyxia's Lair in Patch 3.2.2 was just the first step. As most of the leveling will take place in revamped areas of Azeroth, so too will the dungeons, allowing players to use them to level from 80 to 85.
Unreleased Zones & Dungeons
With the addition of flying mounts to Kalimdor and the Eastern Kingdoms and the redesign of many zones, most of the previously unreachable or incomplete zones will now be made available to players. This is where most of the new content from 80 to 85 will take place. Some of these are,