That game looks like a good use of kinect, you're on rails so you don't need too much flailing and your angle of lean translates directly into the game. Although the jump in a circle to do tricks seems like it would be dangerous in my house.
I guess that's the problem I have with kinect and probably any motion control - it can do exactly what you do, but it is also limited by what you can do. If you start adding inhuman abilities (i.e. 720 edge grab) you need to rely on gimicks. The wiimote and move at least have some buttons but kinect is going to need special gestures which seems lame.