Sonalon (http://www.sonalog.com/) has developed the GypsyMIDI motion capture MIDI controller. One arm costs £480, both arms with wireless control cost £1240.
The Quicktime videos on the site are very funny, like modern dance meets Jerry Lewis. But this is not a wild art project seeking grant money but a real produced by Animazoo, who make high-end motion capture gear for animation companies.
Now Styxx can dance the Freddie, the Macarena, the monkey and the robot and hear music while he is dancing!
This is the direction for new multi controller instrument interface.
Association between natural and instinctive movements of our body and advanced virtual instrument controllers will make music creation in real time possible and programming easier.