Gamespot recently had a chance to play Virtua Tennis 4, utilizing the Kinect and Move functions in the game.
"Performing different types of shots was as simple as adjusting the swing of our arm, or twisting our body around for backhands. Faster swings resulted in faster shots, and by angling our arms we could direct the ball to different parts of the court. We did try our hand at adding backspin and slicing shots, but found them quite tricky to pull off, at least without much practice. Using the Move offered a similar experience, though with the navigation controller you can move your avatar around, but sadly this wasn't something we could try out."