Remember how Blizzard trademarked the name Cataclysm in July? It appears it's the name of the next World of Warcraft expansion.

WoW.com, citing "multiple sources close to the situation," claims that World of Warcraft: Cataclysm will be the third expansion for the wildly popular MMORPG. They also state that Cataclysm will add two new playable races to the game: the werewolf-like Worgen will join the Alliance while the Horde will accept the little green Goblins into their ranks.

BlizzCon 2009 will take place on August 21st and 22nd. If this rumor is legit, one would expect some sort of announcement from Blizzard during that time.