Hmm, It wouldn't surprise me that they went this way due to the lack of power in Nintendos consoles, the simpler Prime graphics would probably look better than a cut down WFC and since there are probably a younger audience for the Wii, it makes more financial sense.

Nintendo, Sony and Microoft always want ot have the exclusive to their console games, so It probably isn't all that much of a drama and most people should be used to it now, afterall, we aren't surprised to see Mario on only Nintendo anymore (I know bad example...).

But I still stand by my point that a Prime game would play better to the resources of the wii than a cut down FOC.