I wouldn't be that surprised ... It is likely that Rockstar could treate the PSP,PS2 and Wii as a collection of platforms with (somewhat) similar performance; obviously the Wii could handle higher detailed models, environements and textures but this can be handled quite easily. The PSP,PS2 and Wii will have a larger combined active userbase than the XBox 360 and PS3 for most (or possibly all) of the generation. Basically, it wouldn't surprise me if any game made it to the Wii but I would expect that (in many cases) the Wii version or XBox 360/PS3 versions would be a spin-off version of the other's game.