Our data center (Internap, the same one we've been at for many years) lost all its power, including redundant backup power, for some unknown reason. (unknown to us, at least) We're currently dealing with verifying the correct operation of our 100+ servers. Not fun. We're not happy about this. Sorry... :-/ More details later.
Update #1, 7:35 pm PST: we have power again, and we're working to assess the state of the databases. The worst thing we could do right now is rush the site up in an unreliable state. We're checking all the hardware and data, making sure everything's consistent. Where it's not, we'll be restoring from recent backups and replaying all the changes since that time, to get to the current point in time, but in good shape. We'll be providing more technical details later, for those curious, on the power failure (when we learn more), the database details, and the recovery process. For now, please be patient. We'll be working all weekend on this if we have to.

Update #2, 10:11 pm: So far so good. Things are checking out, but we're being paranoid. A few annoying issues, but nothing that's not fixable. We're going to be buying a bunch of rack-mount UPS units on Monday so this doesn't happen again. In the past we've always trusted Internap's insanely redundant power and UPS systems, but now that this has happened to us twice, we realize the first time wasn't a total freak coincidence. C'est la vie.