Darren (again) pointed me to the Movable Type 4 Beta that was released. It's got some nice features, a new interface, supporting OpenID, a dashboard overview, etc. Eric has only this to say about it, and while I'm not that uninterested, I'm not hugely excited. One thing that was a nice little feature was the ability to reply to a post from within the admin UI. Since generally a blog owner will be replying to other people, this makes far more sense to me.
I threw MT 4 on a test server and imported my current blog into it to play a bit. The UI is nice and new, but a bit slow in parts, and there are a bunch of perl errors that are thrown out doing fairly simple and one would assume, well tested, operations (ie: approving a comment).
I'm going to keep my eye on this, but probably won't get too involved until beta2 comes out at least.