Quarion let us know about downtime tomorrow:
The authentication system will be undergoing maintenance on Friday, February 1 2008 from 10:00AM - 12:00PM Eastern (-5 GMT). During this time, players may encounter difficulty logging in, while those already in the game will be unaffected.
We don't anticipate any game server downtime during this maintenance, but may bring the servers down if necessary. Please play accordingly (for example, this is not a good time to take on Thorog or the Black Abbott!). Thanks for your cooperation!