Note this is why. I say DO NOT BUY ANY GAMES CONSOLE RIGHT OUT THE BAT. Wait a year or two.
To expand on this a bit:
The reasoning is because game developers have to learn a completely new architecture for development. Some stuff may be portable from the 360 but not everything leaving for most of the wheel needing to be reinvented. Once standards and governance get established again, the full might behind what you can do with the consoles will show better in games.