When will Yahoo be done updating?

There's a message on my Yahoo Messenger service that comes up when I've been trying to use it this evening:

"The Yahoo! Messenger service has sent the following error message:

Yahoo! Messenger will be performing scheduled maintenance
on December 8 from 5:30 PM PST to 7:30 PM PST. During this
period, you might experience problems when using Yahoo!
Messenger."

Hitting the "OKAY" button under that results in a rapid flashing of some error message, from Yahoo, followed by nothing.

It's worth noting that it is now after 9:00 PM PST.

I went to the Yahoo! website to see what the story was, but their help system is not designed to let you know about systemic outages.

Argh.