Boris just upgraded this blog to Movable Type 3.2 which just came out. It has a bunch of new features and is very stable. One important new feature is advanced community management that deals with comment spam. Anyway, for people who have been waiting to upgrade, I think it's time. The upgrade is pretty easy and free for current licensees of 3.x. The new license also allows an unlimited number of blogs. If you need help, Boris is helping people out (for a fee).
Disclosure: I'm an investor in Six Apart and Chairman of Six Apart Japan.