I really doubt nintendo are going to "drop" motion sensing after the WII, (thats if your saying something different meaning different from the already WII) Nintendo has obviously hit the right path with the WII, the new console prolly wont be called WII 2 but it will be an expanded WII.You could argue and say a Wii 2, but I don't think that will happen.
I still dont see nintendo adding DVD playback to any of their systems, they have said it a million times, they make gaming devices not media centers.
So, i think nintendo will overhaul the wiimote, more features, maybe full HD graphics, expand the WII connect 24 (including VC games etc).
there is no reason for them to make a "completly" new console, they only need to upgrade this one, oh and i hope the "WII 2" has backwards compatibility with WII games and GC ones. Maybe GC games will be hitting the VC for the "WII 2"