I'm gonna buy the WII for Legend of Zelda Twilight Princess.
indeed one of the best games that exists in terms of deep content and gameplay ,
story etc ...
For the WII on windows, i think you can adjust the mouse sensivity or someone will make a better driver/little software for it i hope

it can only be a very good thing : gameplay can fill lot more natural
than a mouse on a 2D plan.

the better would be ot use also the other thing that you put on top of your TV:
better presicion , depending on where you point on screen and not how you
roll or pitch the WIImote controller.

for any FPS , or samourai, medieval games (Drak Messiah) it can only enhance gameplay and immersion

I think this sort of thing will exist on PC also.