10:22 a.m. PDT - We are in the process of performing an emergency maintenance for all North American Diablo III servers to resolve several issues that are currently impacting the game. This maintenance may cause some interruption in communication, ability to log in, use of in-game features, and disconnections. We anticipate all servers will be available for play in approximately 1 hour.
Servers are actually still down, according to the server status page. Wow.
Do you really think it's server overload? I find it hard to believe they were that unprepared for the traffic.