As Grits has noted ...
Google's Blogger service has been offline or unreliable for much of the day, with Blogger-hosted blogs changed to read-only mode, and posts and comments made after 7:37 a.m. PDT on May 11, 2011, removed.
In a post on the Blogger help forum, the product team said that it had rolled back a scheduled maintenance release from last night and that its "engineers are working hard to return Blogger to normal and restore your posts and comments."
Google's reply for a request for comment was, "The team is working on this." The company has posted some short updates to the Blogger Twitter account and Status blog, but hasn't yet explained what's happening, how widespread it is, or what will happen to users' content.