Polaboy. A giant, illuminated polaroid for on your wall. Or walls. With 5,000 lumens of LEDs to provide the light source, the images are printed on a special slide film, and can be swapped out at will. The whole rig is only 20mm thick, running 12 volts, 45 watts. Order the frame on polaboy.de. Only downsize: The price. Just the case on its own is $2500.
I guess we creative people are already thinking about a way to make it ourselves (pick up an LED powered, 27×40-inch backlight for less than $400. After that it would be a matter of creating the frame, and then getting your image printed onto a sufficiently large transparency. It might not be quite as slick, but it would be affordable.)