The market leader is never the most powerful console, and developers always port down their games to the market leader to get to the bigger userbase. This generation it's taking a little longer due to the unexpected success of the Wii, but it will happen.
RE4 was ported down from GC to PS2 and looked like crap. It happens all the time.
Call of Duty 4 was "TOO POWERFUL FOR THE WII" and now CoD5 is coming out on the Wii at the same time as the other platforms and the developers say it's exactly the same game but with different graphics.












