Some days I wish I hadn't completely scrapped and deleted my Mac-only Clojure-only native IDE. It was fricken cool, even if it wasn't Emacs. I think that thing had promise. Welp.
I've been a fan of (disappearing) Cocoa-built IDEs (http://lists.apple.com/archives/java-dev/2007/Aug/msg00025.h... was another one)
Scrapped, sure, if you felt frustrated with it, but why did you completely delete it?