Missing The Point
To say that the Wii isn't next gen is surely a tad patronising, Microsoft and Sony have given consumers exactly the same type of game that they've always played, on practically the same box shaped console they've always used. They've given them HDDVD/Blueray, sure, but ultimately it's just a graphics upgrade. The gameplay's the same, but with additional (and costlier) disc formats.
Nintendo have given us the first step in true environmental gaming, with the next generation in controllers AND for the same price as the original playstation! They've opened up a whole new arena in what can be done and it's now up to games creators and developers to let their imagination go wild.
Sony and Microsoft can only make their games (no matter how fantastical) more 'real' graphically. Nintendo can do what ever they want because the Wii gamer's physical interaction is so much more involved than that of the other main players.