Apparently Blizzard will be accepting applications for beta testing for World of Warcraft this Wednesday (Jan 28, 2004). This was posted in their forums:
At 6:00 pm PST on Wednesday, January 28th, the signup period for the World of Warcraft Beta Test will officially begin. We will provide a link to the beta-test application right here in the news section at that time. Testers are not going to be chosen on a first-come, first-served basis, so you will be able to submit an application and receive equal consideration anytime during the signup period, which will end on Wednesday, February 4th at 6:00 pm PST. Please note that multiple submissions from the same household will result in complete disqualification.
For this initial phase of the World of Warcraft beta test, we will only be able to accept applications from Canada, Korea, and the US. The test for Europe and other countries around the world will happen later this year. Please do not contact us for further information regarding the beta test; we will be posting a FAQ in the days ahead.