Bah..This have been talked so much.
1:Just think how long games like Mgs 4 were developed and after that they got hang on Ps3 and then they should think how to make it ok with Wii controls and graphics...
2:Some games need power to be good.
3:Wii controls are bad for fighting games like Tekken or SF4 or Devil May Cry.
4:Many of those games developers have been doing same stuff from Ps1>pS2>ps3 with just graphical and gameplay changes.They would need to start from beginning if they would try put sequels of past generation to Wii and that would piss of many of their fans.
5:Wii doesn't have such audience for sequels of Ps2 series or certain type games.
Take my love, take my land..