There are to many people playing on the east coast servers and some of them are down. The one I'm on is down. They said to play on west coast servers and they will be bringing up new serevers to help handle all the people.
No I cant get on either. And honestly this is the only complaint I have with Blizzard staff is that they dont post ASAP on the boards when something has happened with the servers. This leaves alot of people wondering.
Doomhammer (Mountain) isn't necessarily down, but it's having terrible lag problems (10 minutes to accept a resurrect.) So picking a Mountain or Pacific server isn't going to help much.