I don't think being the biggest one generation guarantees anything for the next (look at SNES - N64 and PS2 - PS3).
Nintendo games generally lose some appeal as kids turn into teens who generally like to blow the crap out of things.
However, the biggest factor here is the controls. After playing FPS and sandbox games with the Wii controls, I find going back to dual analog is like taking a big step backwards and I'm a long time gamer. Unlike last generation where many kids owned Gamecube and 'advanced' to PS2, this time I think there will be some frustration for this generation where PS3/360 have prettier, more violent games, but then you have to learn how to use (what may seem like) a more primative, inferior controller to play them. It'll be interesting to see how this plays out. However it goes, I think the parents will continue to play with the Wii's themselves.







