What would be really cool is using a setup like the the lead guy, but more in depth. The person would have multiple remotes attached to different parts of their body, then they'd do the robot or some similar dance to activate different instruments or pitches just by different gravitational pulls.
It would be like a modern one man band... only with wiimotes and synthesizers... and cool.
http://www.youtube.com/watch?v=azb9kN1fgwc