Yeh, Wii wont ever be able to compare with 360/ps3s graphics... but it doesn't need to, and it's proven that through sales.
The innovation of the Wii's controls are more than enough to keep gamers playing the ecxiting games the bless the Wii. And these are only early games. In one or two years, you'll see good looking games with some incredibly addictive controls.
Yay for Wii