Unveiled at the company's fourth BlizzCon gaming festival,Blizzard Entertainment has announced plans for the third expansion to World of Warcraft, its massively multiplayer online role-playing game.

World of Warcraft: Cataclysm will bring sweeping changes to the world of Azeroth. Players will be able to adventure as two new playable races, achieve new levels of power, take on challenging quests and dungeons in all-new zones, and experience dramatic changes to familiar aspects of the game in the wake of a world-shattering disaster.

In Cataclysm, players will witness the face of Azeroth being altered forever, as the corrupted Dragon Aspect Deathwing awakens from his subterranean slumber and erupts onto the surface, leaving ruin and destruction in his wake. As the Horde and Alliance race to the epicenter of the cataclysm, the kingdoms of Azeroth will witness seismic shifts in power, the kindling of a war of the elements, and the emergence of unlikely heroes who will rise up to protect their scarred and broken world from utter devastation.

"In addition to revitalizing some of the most familiar and iconic areas of the game world, this third World of Warcraft expansion will add new features and a large amount of new content for players to explore," said Mike Morhaime, CEO and co-founder of Blizzard Entertainment.

World of Warcraft: Cataclysm is due for release in 2010. Blizzard confirmed that Starcraft II will also be released next year.