update: My favorite website VE3D has an excellent high resolution trailer of the next gen version of Sonic Unleashed for you to compare both.
Tthe Wii version of Sonic Unleashed appears to be one of the better looking games for the console. It runs at 30 FPS however, which is rather a disappointment. There is also no physics engine, and non of the special next-gen effects of the 360 and PS3 versions. But if you can go beyond those, it sure doesn’t look too shabby! Check out the new footage from IGN: