I've been using ViewPoint to make 3d models for some time, but I'm intrigued with the prospect of moving those models to Silverlight. I have pretty good asp.net experience but have never created a Silverlight App. Are there any good tutorials out there on creating 3d models in Silverlight 3 beta?
You can do this, even in Silverlight 2, using the Kit3D engine for Silverlight.
This library provides Silverlight with a 3D engine very similar to WPF's Media3D tools.
See Reed's answer - Kit3D is your best bet (whether Silverlight 2.0 or 3.0) - check out some examples.
If you've read about the new '3D capabilities of Silverlight 3.0', it is not actually a complete 3D system (a-la WPF) but rather a new type of Transform that (basically) "renders a flat surface in 3D space".
It's called PlaneProjection and lets you do stuff like this and this. It is great for flipping stuff around (like a carousel control) and similar effects (also implementing Photosynth where the deepzoomimages need to be positioned in '3D'), but NOT really capable of rendering a 3D model as such.
If you decide to play with Kit3D (or WPF's 3D stuff) the Charles Petzold book really helped me understand the basics of it all...