Obviously, you'd have to make it playable with the wii remote. Everybody with a wii has a wii remote, but not everybody has a classic controller. You know, maybe it would be better if you could offer it on the wii/xbox360/ps3 network, but also as an extra game bundled with one of the great games coming out for each of these consoles. That way you would reach the biggest audience(together with pc of course), but I'm not sure if it would work as those companies would probably demand exclusivity for their systems, which would suck.
Although exclusivity usually helps selling more of your product, I think.
Either way, I will buy it for pc so I'm not really fussed about this game being available on Wii, personally.