I've wondered the same thing myself, as a professional in the field of architecture. But I honestly don't see a fully functional 3-d model viewer happening on this hardware. Perhaps something flash-based that could be accessed via microb?

2D cad viewer might be possible, but Autodesk seems to be getting more and more closed as their products progress. Exporting to PDF is still your best bet, as that's how we tend to share things in our workplace.

If you're using sketchup, your best bet would be to set up a slideshow with pre-determined views, and then export it to an AVI that the media player would read.

Hmmm.... I'll have to give that a try when I get to work on Monday

I'll post back with results.