If there's anything I can do to help get anyone started that's interested, let me know. I'm JUST getting started playing around with XNA too and would love to learn together with some outside folks. I have a lot of experience writing .NET (managed) code and would love to help if you have any questions from a coding standpoint. There will probably be lots I can't answer, but can probably help you find the answer. 
Of course you'll also want to check out our developer content on XNA on Channel 9.