Hum. I think it's far too early to judge that.
1ST POINT
1st, Wii version of SW wont cost as much as 360-PS3 versions to develop. Also, it s combined with PS2 version most of the time (which is downgraded).
Meaning Wii version need to sell around 4 to 5 times less and still be more successful .
Your assesment is wrong from the beginning.
2ND POINT
Wii version tend to have far better legs. See SW FU in Europe : Wii version is now outselling PS3 and 360 versions.
On long term, Wii version should outsell both...
RIght ?