3D-printing is awesome, but it has its limits. For the time being, we mostly get static plastic figures, and while resolution is getting better all the time, we're far from a real replicator future. A new development is bringing us one step closer, however: printable optics.
A paper recently published by Disney Research — the folks who brought you the plant-computer interface — describes how certain techniques could lead to 3D-printed objects that respond to touch and manipulation with a lights. The simplest technique basically involves bottom-lighting a figure, and using specially printed "Light Pipes" to direct the light to the surface where you want a display.
The resolution leaves a bit to be desired, but hey, this is a new technology. It'll only get better as time goes on. If you want to read more about the tech, you can find the entire research paper here. Suffice it to say, the sooner this stuff catches on, the better. [Disney Research via Core 77]