I've had this problem all day as well, but its only for one character. I can create new characters, and log in with them without any problem. So, I assume its a character data corruption issue.

When I try to login with my primary character, I select the character, and get to the 'Now Loading' screen, where it sits for 50 seconds, and then times out, giving me a 90k error. If I try to log back in real quickly, I get a 3102 error (still logged into game). So, some part of my character is actually logging in, its just not making it back to my game client.