What you get from Vizard's physics engine is essentially a wrapper around an open source project called Open Dynamics Engine. We expose many of its functions and parameters. If you want to get an idea of what's it's capable of generally, then look here:
http://ode.org/
Our implemenation of this is truly in an alpha stage right now and is likely going undergo a significant re-write of the calling syntax, but as much as possible we'll try to maintain backward compatibility with the current calling syntax. Keep in mind that we only support part of the ODE package.
You should look at the two sample scripts we provide, physics1.py and physics2.py, to get an idea how things work. Unfortunately, that's all we can offer at this point in terms of helping you find out what components of ODE we're supporting. If you have specific questions, you're welcome to post again. Otherwise, thanks for your patience and you'll have to wait until early '05 when we release the physics engine officially and provide documentation.