3D Flash is something we're keeping on our radar, especially since my company started off as a company specialising in
3D interactive media back in 1998, before we moved our focus to business websites.
Flash and 3D, whether it is with Papervision engine, or other
Flash 3D engines, is interesting because it makes 3D available via technology that is present on a lot of user's browsers. Perhaps one of the most important features of a Flash 3D engine is the fact that it can display 360 still panoromic images without users requiring the QuicktimeVR plugin or Kodak iPix plugin or Java plugin.
The '3D video' isn't really 3D, just as a 360 degree panoramic still image isn't 3D. The '3D video' is more like a 360 panoramic movie. As such it will have similar levels and limitations of interactivity that 360 panoramas have.
As for potential uses there will be niche areas, but it will be a long time, if ever, before 3D goes mainstream as a web medium. We learnt a long time ago that 3D isn't always the right way to go, however initially impressive a demo might be (although we do have some ideas of where 3D can go). Lessons can also be learnt from the 360 degree
still image panoramic market, surely something that impressive introduced years ago, and improved since then, would be the only way people buy and sell houses on websites by now? But the property market tells a different story, you don't get a 360 panorama with every house for sale on the internet, and if the seller isn't putting in this effort in order to sell a 5, 6 or 7 figure sum property product, you have to ask yourself why not?