There's too much to go wrong. Look at the beginning of it - there is a disclaimer saying it's just what they want to make at the moment. Not only that, but I doubt it will become that big of a thing - just like not all PS3/Xbox games are on the wii, not all games produced would support new technology like that. Similarly, the price tag must be massive on that to fund all the research and development that would go into something so complete as that (if it even gets to that stage). Lastly, if Sony thought it was a major threat then there would already be rumours of a PS3 version of it or a different, more advanced thing like 3D gaming using mini projectors or some other, crazy idea.
Oh, and I can see the main problem being that people will get mega pissed off with it. Playing CoD, for example, is tiring enough on the Wii while just holding up the 'gun' for an hour or two, but asking people to also do all the running etc to move would either actually get most people in shape or stop them playing. Not to mention I don't see how effective moving would be when if you turned around, you wouldn't be facing the TV nor would their be enough room to move around the whole level.
By reading this signature you agree that mixster is superior to you in each and every way except the bad ways but including the really bad ways.