
Reverse compatibility is something that bothers the shit out of me about these new consoles, and might mean I buy a PS3 eventually, but never a "new gen" console.
As for gimmicky bullshit, the IllumiRoom Microsoft showed off (basically a projector that covers multiple walls) does not look ready, but it's a neat concept ... it is gimmicky, though, and not something I'd pay any sort of premium for in the near future until all the kinks are worked out.