There is also nothing about licensing your own work. Can I create a Creative Commons AT-SA video using this as the backing track? What if I also release all the source to my video under the same CC license? Can someone else that that track and use it in his/her project with the CC-AT-SA license? What exactly is attribution at this point? The video using the track or do you need to credit Filmstro too?

I agree, the FAQ doesn't go into enough licensing detail.

I do like the concept, but I think I'll stick to ccMixter.