An earthquake is coming for the video game business. Blizzard Entertainment is readying a new expansion pack for its market-dominating World of Warcraft online game, and the company is launching the beta test for it today.

World of Warcraft: Cataclysm is going to create shock waves for rival game publishers as it launches later this year, sucking the time out of the 11 million hardcore gamers who are fans of World of Warcraft, which generates a billion dollars a year in subscription revenue. Blizzard Entertainment is a division of Activision Blizzard, the largest independent publisher of video games, and World of Warcraft is the main reason that Activision Blizzard is so large.

It’s an easy bet that Cataclysm is going to cause a big crater. It will command the attention of fans, much like the upcoming July 27 launch of Starcraft II, another expected blockbuster from Blizzard. Game publishers have to stay away from its launch date (which isn’t exactly clear yet) to avoid falling into the crater (i.e., getting lost in the noise).

When Blizzard launched its last expansion pack for World of Warcraft — the Wrath of the Lich King — on Nov. 13, 2008, it sold 2.8 million copies in the first 24 hours. That made it the fastest-selling computer game of all time, beating the previous record set by World of Warcraft: The Burning Crusade, which sold 2.4 million in its first 24 hours.

In short, Cataclysm is going to be a renewal of Blizzard’s license to print money. The company is starting to issue invitations for participation in testing for players from around the world who signed up via their Battle.net online gaming accounts. Cataclysm will be unique in terms of its story because the return of the corrupted Dragon Aspect Deathwing will cause devastation across once-familiar regions of the existing fantasy world. There will be two new playable races: the wolf-like Worgen and goblins. The level ranks will rise from 80 to 85. After reviewing the beta test results, Blizzard will set a launch date for later this year.

You may not care about Worgen and the like, but if you know someone who is addicted to World of Warcraft, then you may understand why they’re going to disappear for a while. If your spouse is into World of Warcraft, well, you have my sympathies.