I keep thinking it shouldn't be too difficult to design one that uses the current UV curing resins (albeit thinned greatly) to create a layer. The printer might need to be like a dark room and the ink cartridge would have to have a safe parking spot each layer so it would not be exposed to the layer UV curing lamps. Also these would come on when the print is complete to kind of bake it solid for a period.

Just a concept. The true adoption driver is going to end up being cost. We're truly in the period of the tech wars in 3D printing. Think Beta vs. VHS or HDDVD vs. Blue ray, while we're seeing so many new choices in ten years we'll probably have a whole new, and much faster, ballgame.