Neither technology is honestly that interesting. Natal is a camera system that is not too different than Sony's own Eye Toy (anyone ever play Eye Toy Antigrav? Go look it up). The key difference that everyone is missing, is that the Wii started out with the Wiimote. This is the fourth year for the Xbox 360 and the third year for the Playstation 3. From jump street, the entire library of existing content is incompatable.
They will have to have some very compelling software to make these devices seem worth purchasing. The other problem, is the market. People buying Playstation and Xbox are clearly a certain type of gamer that seeks the experience that is currently there. The Wii was aiming at bringing back old Nintendo fans, raking in non-gamers and picking up whatever other willing customers it could. Microsoft and Sony are trying to change audience mid generation and I don't see it panning out like everyone thinks. In a sense, this industry is suffering iPhone syndrome. There is a king on the throne and everyone else will make desparate efforts to take his place. Natal and the Wand will be no different to the Wii than the Samsung Instinct or Palm Pre were to the iPhone. Sure they are nice, but they won't dethrone anything.
