NI-mate gives and excellent full body skeleton including Multiple user support for MIDI & OSC controller modes.

They have an ambition 2012 roadmap, much of which is already in place in V1.02

NI mate roadmap 2012

Planned:
v1.1 Multi-user support for exact & controller data
v1.1 Multiple simultaneous feeds through Syphon and the FreeFrameGL plugin
v1.2 Recording and playback of captured data
v1.2 Controlling NI mate parameters & changing profiles through MIDI & OSC
v1.3 More MIDI & OSC controller options
v1.3 BVH-exporting

Further research:
- Head/wrist orientation tracking
- Support for multiple sensors
- Improving tracking by using multiple NI mates
- Face detection & other means of identifying users
- Integratin other input devices to improve the tracking (for example smart phone with accelerometer)
- Speed increases from multithreading and from using the gpu

here are a couple of videos about it use