Part of the reason for my absence from dollarshort.org is that I've been busy working on the movabletype.org redesign. Also, we've just released MT version 2.2. Along with MySQL support, we offer a new feature called TrackBack. We're excited about the feature particularly because of its potential -- we can't wait to see what people will be able to do with it.
Because TrackBack seems to require a fairly large user-base to be most useful, we're hoping that other developers will want to integrate the feature (or at least compatibility) into their own tools.
But for present, I'm just hoping to get some sleep.