Keep in mind that the Wii is largely limited by technical short comings that prevent developers from doing genuinely neat stuff with it. Natal and Move are far more flexible. I wouldn't call it "Wii2" or something silly, they just need to be utilized properly. Whether that is done or not remains to be seen.
That being said I wouldn't be one of those launch day buyers of either products. Wait a year and see how it shakes out.