Man, I wish my Google skills were a bit better. Instead of spending hours solving a problem, I would have spent minutes implementing someone else's solution. So it goes.
For you OS X Server admins out there, if you run FTP services the most recent security update is going to cause some pain. After I updated my servers, I went about testing all services to make sure everything was running correctly. At first glance, everything was fine.
Then I tried to update my website and got some really strange errors from Blogger. It kept telling me the path to my website did not exist on the FTP server. I manually connected with Transmit to make sure everything was working--and found myself staring at the root of my disk! I assumed some configuration file got hosed, so I launched Server Admin only to see that all my FTP server settings were dandy.
Logging into several servers all yielded the same result.
Lucky for me, I clone my server boot drives before applying updates. I started using diff to see what had changed between the updates. I found that the ftp.plist file in /System/Library/LaunchDaemons was different so I looked at both versions. I was shocked to see that ftpd was being invoked instead of xftpd. Copying the file from the cloned, pre-update, drive and rebooting fixed the issue.
Here's a great discussion I found on the issue this morning, along with the text needed to resolve the issue.