Theme Browser is Back Up
The WordPress theme browser is back up and running again after ~48 hours of downtime. For those who are curious, here is what happened:
Last week, I had to rewrite the theme switcher plugin because it was killing the server it was running on. The original theme switcher code was traversing every directory in each of the 135+ theme directories looking for themes, which basically keeps the disk working way too hard. I’ve basically cached that information now, so the poor other folks on one.textdrive.com won’t have to suffer because of it.
Right after that change was made, the cookie domain got messed up in the code. That was at exactly the same time the servers were being moved to the new TextDrive data center, so I wrote it off as a migration bug that would probably get fixed. When it didn’t get fixed, I dug further and found the problem (now fixed).
Now you can go on and get your fix. 
UPDATE: Strange, it works fine if you click on the theme links on the page, which use the same URL as the theme browser code, but it doesn’t seem to want to work in the frameset. Unfortunately, I can’t get into the server right now, so I’m not able to debug or fix it.
UPDATE #2: Finally got in and was able to “fix” the problem - commented out a header call that has been there since the theme browser was first brought online. No idea why it needed to be changed now, but it seems to work again.