Yes.

Yep.

yes D:

YEP

"We are planning to perform routine Steam server maintenance and updates today, July 31, 2012 at 4:15 PM PDT (GMT-0700).

Chat, game lobbies, matchmaking, and the community web site may be unavailable during the maintenance. In-progress content downloads may also be temporarily interrupted. Game play should be unaffected, although some multi-player titles may experience interruptions."

oh god brace for 10 of these threads

And, yes. It happens. It will come back up.