I think the 360 version of GTA will be better than the wii version.
I'm not agaisnt having a version of GTA on the wii, but I think it will be inferior to the 360 version, mainly because the graphical limitations of the wii preclude a direct port, which means that the only way GTA will ever come to wii is if they port san andreas, or make a GTA specifically for wii.
I doubt either will happen, especially the later. It is extremely unlikely that rockstar will put an A-development team to make GTA wii.
So basically, why do we need a wii version when the 360 version will be superior? if you want gta, go get a 360 (or if you don't have a brain, then the ps3 will suffice).
whilst a nice idea to have gta wii, be objective guys. it's not going to happen, and if it does, it's not going to be a AAA title in the same way GTA IV will be.