I just watched a video about this game.
It seems really cool to me. Instead of completely controling a character through a platformer you are manipulating the land and the character for a more puzzle feel.
I really like the concept, and it sounds like it could have some very challenging and devish game design moments.
Hopefully Nintendo does this game right, because it could be a great game. Its on my to watch list definately.
I am still trying to decide what games to get at launch I will probably get 2 possibly 3, but which ones besides Mario is a big question.