We will performing maintenance on the Mists of Pandaria beta beginning at approximately 7:00 a.m. PDT tomorrow morning. We anticipate that downtime as a result of this maintenance will be relatively minimal, lasting between 1 to 2 hours, and that all beta realms will be available by approximately 9:00 a.m. PDT.

Thank you for your patience!

Today's maintenance thread:
http://us.battle.net/wow/en/forum/topic/4768627920