"We are very sorry that users are unable to publish to Blogger right now. We have rolled back the maintenance release from last night and as a result, posts and comments from all users made after 7:37 am PDT on May 11, 2011 have been removed," Google said in a support thread.
"Again, we apologize that this happened and our engineers are working hard to return Blogger to normal and restore your posts and comments. We will post a report once this work is complete," it added.
Google had a scheduled maintenance downtime on May 11, from 10 pm to 11 pm PST (Pacific standard time). During this time, the service was in read-only mode, but the blogs themselves were accessible and working properly. The update introduced a number of issues and instabilities and the service was unreliable for many after that.
The problems turned out to be bigger than Blogger had anticipated and the site was put into read-only mode again to fix the problems. Blogger has reverted to the stable version prior to the update.
However, this also meant that all of the posts and comments on Blogger starting 7:37 am PDT on Thursday May 11 were gone. The content isn't lost, everything is backed up, but has to be restored.
Of course, since the site has been in read-only mode for quite a few hours now, no one has been able to post anything since Blogger decided to roll back the update.
At this time, the freshest content on Blogger is from two days ago. Interestingly enough, Google itself hosts all of its blogs, tens of them, on Blogger. Any post Google has made for the past two days, including the Blogger Status blog, on which the latest entry is from May 9, is unavailable. If you subscribe to a feed from any of the blogs, you will be able to read all of the posts there.
You can check out the Blogger Twitter account for updates. It's ironic that Blogger has to turn to Twitter to keep people informed since for a long time Twitter was the one with serious reliability issues.