Ok, urchin is definitely ready for business. I ditched the weird text file format and just marshal/unmarshal ocaml objects. It works much better.
I also ditched blightmud. It's just a little too flaky, so I'm back to the tried and true tinyfugue. I mean, it's essentially abandonware, but there are a few people out there patching it and keeping it running. And really, how much more development do you need?
The only piece I'm still not happy with, is the lack of compression support in urchin. I'll have to figure out a way to factor than in, but for now it's useful enough to do what I need it to.