With Daniel Lehenbauer starting a nifty GotDotNet 3dTools project and with Mike Hodnick writing a great tutorial about WPF 3D that references my out-of-date Sandbox3D project, I finally ported Sandbox3D to the Jan CTP.
I was able to get rid of a ton of databinding code and do all the data binding to the various transforms all in XAML. Nice! Another thing is that I don't use Daniel's trackball code but rather I use the one RHogue uses that a dev within MS built a long time ago. This trackball works slightly differently.
There is one bug outstanding, which is some databinding property pathing where my sliders on the Axis vector 3D are not quite working. They work with the trackball but not manually. If anyone figures out my bug, let me know!