How do you get a personal invitation to the beta?

In earlier days Sam Raimi spoke at length about the upcoming World of Warcraft film adaptation. But for those who would rather play than watch, on june 30 Blizzard began sending out invitations to try the massively multiplayer role-playing game's upcoming expansion, Cataclysm. The action starts. Selected individuals who opted in to playtest the add-on via their Battle.net accounts are receiving invitations, and Blizzard says it will add more week by week. Those interested in getting in on the action can create a beta profile on their Beta Profile Settings on Battle.net and hope for the best.

Blizzard says beta testers can help shape the final product by providing feedback to the studio in the form of reporting bugs, commenting on balance issues, and contributing other constructive feedback.

Cataclysm is World of Warcraft's third expansion, following 2007's The Burning Crusade and the following year's Wrath of the Lich King. The new add-on, available both as a boxed retail product and as a download, is due out by the end of 2010. It brings new zones, ups the level cap to 85, and adds the Goblin and Worgen races to the popular MMORPG.

In other Blizzard news, WOW lead designer Tom Chilton hinted at the possibility of the game becoming free-to-play, though he said no immediate plans are in motion.

From: Gamespot

You can find all the information about the release here