I think Nintendo is the best developer around, but even them in my opinion wont be able to make a flawless game that uses both the GC controller and the remote, for the game to trully use the remote it must be completly revamped, it would be so mediocre to map remote functionality to things that a button can do, like Ian has mention so many times. Why swing a remote to simulate a slash when you can do it with a button? It can only make a difference if also enemies' attacks are changed accordingly, which means revamping the whole combat mechanics, probably going as far as changing bosses mechanics completly. Is the same to any 3D sensing functionality anyone can think off.
And sadly that will detract from the core game too, the attention is split, is not really a GC game any more, but neither is Rev game. That rev functionality is the dumbest idea Ive heard in the history of dumb ideas, and royally screws up the GC owners who wanted the game, is worth of companies like EA, not Nintendo.