Yes Blizzard has opened the signup process to beta test the upcoming expansion to MMORPG World of Warcraft. No one is guaranteed a place on the beta short list.
Lich King introduces tons of new stuff, including a new Death Knight class. Both North American and European users have the chance to opt-in the beta selection pool.
To get a chance of being randomly plucked by Blizzard for the whirlwind life of a beta tester you need only to sign in to your respective European or North American account pages for WoW subscribers.
At the bottom somewhere should be the option to throw your hat in the ring, thanks to fans over at World of War for spotting it.
Once in you should get this message: ”You have successfully opted in for a chance to participate in the Wrath of the Lich King Beta. In the event that your account is selected, you will be sent an email with further instructions. Good luck!”
Source: Shacknews