I think that the fact that Natal is coming out several years after the 360's introduction will help.  The Wiimote/accelerometer-based-control has been marketed as an integral part (probably the most recognizable part) of the Wii experience.  In keeping with that, most people don't own Gamecube-style controllers, so making games that use a more traditional interface is a losing proposition on the Wii.<p>In contrast, Natal is a purely optional add-on, and I'm not sure on this but I'm not sure it will be possible to control non-Natal-enabled games or the Xbox 360 dashboard without a traditional controller.  This way, game developers can choose the controller paradigm that makes sense for the game, and the Natal ecosystem can grow organically, rather than have it foisted upon people.  Maybe this is a recipe for languishing and fragmentation, but I can see how this strategy could work out better for Microsoft than Nintendo's did for them.<p>The technology could also be intrinsically much better, who knows?