If you're using Movable Type and held at version 2.661 because of that whole licensing thing, but you've been thinking about just biting the bullet and going for 3.x, my advice is: Don't.
Well, if you're starting from scratch, I'm sure it's fine. But if you're a hand-coder and made all your various templates just the way you like, beware. There's a wholly ridiculous set of changes you'll have to make to several individual templates (on each blog) because of the new commenting system. And so far, even after making those changes, I can't get the new-and-improved setup to work at all.
All I wanted was basic comment moderation. Instead, I got broken templates and their TypeKey authentication crap (that I don't even want)... and I'll probably end up relying on the still-in-beta Blacklist plug-in, anyway.
More and more it's clear, WordPress is the way to go. But since I just shelled out actual money to upgrade Movable Type, I'm resigned to make it work.
Not tonight, though, that's for damn sure.