I just downloaded and played the demo for motoGP with xbox 360... it's awesome. Granted I only played for a short while, but the graphics are great, and it's not as easy as I thought it would be.
Acceleration is done with the joystick, so you have to be real careful not to go too fast around the turns. I like it! I'm now glad I put myself on the waiting list for when the game comes out.
Pictures from xbox dot com
You can view all the pics with the arrows at the bottom right.