Are the devs focusing on wii more than gc? I don't think so, however some dev could clarify this. Some gc games, specifically my zeldas (windwaker and tp) now have partial sound, and so the wii counterparts I suppose for what I've been reading.
Rig
*Corei5 3570K *Nvidia 9800GT 1GB DDR3
*Motherboard Asus P8H77M-PRO *Win7 x64
*RAM 8GB DDR3(1600)
