Would use video in PDF to add 3D overviwe of projects in documentation submitted to clients. Anyway, I've never used those advanced PDF features, so maybe could come up with something else after a few practice...
Right now, the 2D/3D CAD world has two huge problems - high buying and maintenance costs. - myriad of different and not interoperable proprietary formats. Working in a R&D office, I usually get files from various suppliers. In my last week emails, I can see nine different types of 2D/3D files, mostly requiring a specific software
CAD is a necessity for most companies, and smallest ones can barely afford those expensive licenses. I think it is a matter of time before an open source project will address those needs, and the result will eventually be a stable, fast, cheap (or free), reliable software.
Of course, this software will be ignored and criticized for a long time before becoming a market standard.
It happened in the server apps (like apache or mySQL) and office suites (OpenOffice) market, and is happening now with vector graphics (inkscape), publishing (scribus), 3D render (blender) and such.