It's Wii exclusive, so I don't know what all this "what-if" talk about multi-platform is about. It's NOT period.
You have to remember that even Epic, one of MS biggest supporters, hasn't even really checked out Natal from a programming stance yet, so I doubt many 3rd parties are really indepth with Natal development. Same goes for Swand/Disco Stick/IceCream Cone too.