There are some really good deals out there for shoppers right now that may not be there come January; it depends on how much you want one right now. Whether you pick it up now or later, IMHO, a comprehensive extended warranty is a must with the 360. Microsoft hasn't announced a tentative date for a price drop, and they're unlikely to do so anytime soon, seeing as its immediate competitor, the PS3, is still somewhat difficult to find through regular channels.
The bundle with Burnout Revenge as a pack-in should appeal to driving / arcade enthusiasts, and most B&M retailers will carry this. Target has their own bundle with NBA 2K7 as an inclusion. I don't think you can go wrong with either, as both games are fairly solid review-wise.