Maybe TM users should think about creating an open source version. I personally tried TM and liked the general feeling of it, but I won't commit to an editor that (1) is not open source (2) is not multi-platform (3) is not vim :-)
There's also <a href="http://macrabbit.com/espresso/" rel="nofollow">http://macrabbit.com/espresso/</a> with is quite expandable and already starting to build a small community. It's at early beginning but it looks interesting.