I'm using it to verify replication between a big sybase instance and a big oracle instance. This isn't rocket science but performance is much better than it was in Python and the code is about the same size.

I'm also and to liberate data from a MeetingMaker server that's only available via a Java api and make it available in Rails apps. Obviously the superior expressiveness of Clojure makes the code base a lot smaller and makes more sophisticated processing of the data far simpler than it would be in Java.

Hopefully more soon.