Well, since Six Apart adjusted their pricing structure, after the initial outcry, and I was given a 50% off code for beta testing the MT 3.0, that brought the price of Movable Type 3 back down to where I found it completely reasonable to license it, so I did. This blog is now running on MT 3.0, and I've enabled TypeKey registration for the comments. This is my first post, hope it works! Update: It appears commenting is broken, I've opened a support ticket with SixApart though, so hopefully should have it working soon. I guess that paid support comes in handy afterall. :)
Updated again: Everything's working now. You'll have to register the first time you post a comment using the TypeKey system. The good news is, this one login will work on all blogs that use TypeKey, so you'll only need to do it once, no matter how many blogs you visit.