Nikon filed a patent in Japan for a projector built in a DSLR. We already have the Coolpix S1100pj point and shoot camera with a built-in projector and Nikon is at least thinking of bringing that technology into a DSLR camera. The cool part is that the projection will happen through the electronic viewfinder (the initial translation was not clear, so I got this paragraph this directly from the Japan Patent Office):
"When the photographing instrument is set as electronic view finder mode, the photography person can see the taken image displayed on a liquid crystal display panel by looking into a liquid crystal display panel from an eyepiece. On the other hand, when the photographing instrument is set as projector mode, the light which supported reproduced image information is projected on the screen of the photographing instrument exterior via the eyepiece of an electronic view finder, and two or more persons can see the reproduced image simultaneously projected on a screen."