[EricH]

According to LAST YEAR's rules, you couldn't do any detail work. You could do high-level work.

Right now, all teams can really do is play with it. We don't know what we're to do with it, so we can't do any detail work. What you start working on now could be rendered useless on January 5.

Could you start? Yes. Is it legal? By the most recent rules, no. By this year's, nobody knows (except the GDC, and they aren't talking). Is it smart? Possibly. Quite probably, though, any work you do now will wind up as practice only. (For example, it could be a field element after all.)