this wasn't what i meant. usually games like those are handed down to a studio with very little time and budget. sometimes, they can actually pull off something decent (apparently treyarch did with modern warfare on the wii, while infinity ward was too busy or important to do it themselves). in any case, it's rarely, if ever the same design team, and they find themselves working on someone else's idea.
what we were both talking about was one designer making something using their imagination. and my contention was they wouldn't be challenging, not limiting themselves, if they came up with a neat idea for the gamepad, but felt it also needed more hardware power to pull off.
the only limits out there are the ones that you impose on yourself.