It turns out that the problems I was having with Celery (most of them, anyway) were caused by a bug in the EXIF.py library, since it was breaking on one of my jpg's (infinite loop near line 1732). Other images, however, seem to work fine.
A couple things are still missing. I haven't tested it with anything besides images, e-mail registration doesn't work (not sure if I want to enable it, though), and I want to try and streamline some of the init scripts a little more. It turns out that Celery is a pain in the ass to properly daemonize, especially when compared with the paster that does it so well.
I may be blogging about this in the near future.