Well not many games are even bothering to push the processor limits. That goes for the Wii as well. Both consoles deserve more usage. It should improve this year as developers become more familiar.
Another bonus. This year 8 core processors are coming out! That means more people will be REQUIRED to learn how to program on a multi core processor for PC which has a dismal amount of games made specifically for the multi core processors. I'm not saying single core are useless. But it's essential to learn multicore for higher end graphics, lighting, and rendering.