We've determined the cause of tonight's outage. The blog was mistakenly deleted by us (d'oh!) which allowed the blog address to be temporarily claimed by another user. This was not a hack, and nobody guessed our password. Our bad.
Jennifer takes you through the story as it happens. She accounts that this blogger snagged the googleblog.blogpsot.com address, and posted a message saying;
Google, fix your blog pleeasssee! <3 (P.S. Just to clear things up, I'm not associated with Google at all. I just wanted to take advantage of this before someone else with less worthy intentions did. The username was giving a 404, so I tried registering a new blog with it. Surprisingly, it worked. Oh, and no posting URLs in the comments or else they'll be deleted.)
Want to see what it looked like prior to Google getting the blog back? Jennifer posted a picture here.
Forum discussion at Search Engine Watch Forums.