(Updated 2/8/05 5:00 PM PST) The issue is resolved and everyone should be able to connect to the service again.
(Updated 2/8/05 3:30 PM PST) Users are now able to signin to the Messenger service. If you hvaen’t been able to get back in yet, wait a while and try again.
Some folks cannot connect to the Messenger service currrently The Messenger Ops team is working on the issue.
Check here for the current .Net Messenger service status.