You should check out the release notes for each release (3.1.0b1 in particular). You're right that there should be a clearer set of things left to do and such. We have a to-do list, and I'm going to work to make it publicly-readable. However, if you want to contribute, you should go sign up at SourceForge.net with a username, and then send me email directly. I'll sign you up, and you can check out the latest CVS.
