Now that the servers are back online, Blizzard welcomed the stress test beta competition winners into the closed beta.

Welcome, Stress Test Beta Contest Winners!
The results are in, and the winners of the World of Warcraft Stress Test Beta Contest have been added to the beta! The winning characters have been copied to the original Player vs. Environment and Player vs. Player servers, depending on the ruleset chosen during the stress test. All invites to contest winners have been sent; if you are among the winners, you should have received an email from Blizzard with instructions on how to join the beta.
Thank you again for all the hard work shown during the stress test, and welcome to the closed beta!