I would hope the Wii version uses the Wii remote for selecting items on the screen. It would also be nice (but not necessary) if multiplayer were supported on the platforms which allow it. Otherwise, I doubt there will be much of a difference.
Firaxis wants to make all of the versions in house.
From what has been said so far, each version of the game (including the DS) will have the same rules. The only difference will be in the controls and the graphics (probably graphics will only be different on the DS.)