I have been experiencing site problems. I am reinstalling WordPress from scratch and will get things back up as soon as possible.
Updated 15:44 ET to add: The core reinstallation appears to be working, with all posts and embedded images back up and running, and Disqus reintegrated into the site. It will take me a while to recover the formatting in the themes, which I may leave undone anyway because it could have been a theme problem that was causing me all this grief. In the meantime, I think it’s safe to stick your toes back in the water!
–John P.