Whilst I always thought it was a good thing for Lionhead to be ambitious with the Fable games rather than sticking to the boring rules that any other game could adhere to, Fable 2 was pretty poor. If Natal turns out to be a fundamental part of Fable 3 then I know that I won't be playing it. If it is just used for some crappy mini game that they throw in that is entirely optional then fine, I won't bother with that part.
As long as they make a game first and add the pointless and slightly quirky things in later rather than finding as many random things to put in and eventually putting something reminiscent of a game on top.
I imagine the thing that Pete thinks will piss people off is that they aren't putting a dog in, because we all know that Fable 2 was all about the dog. And something about heroes I think, but that was more of a side quest.