Based on some really cool advancements in 3D technology and computer graphics, we have a couple predictions:
1) Within the next 10-20 years we will be watching movies in "theatre in the round" environments. Images will be rendered in full 3D, as anticipated by Sony's RayModeler autostereoscopic display prototype.
2) Filmmakers will be making new movies starring actors long-dead, like James Dean, Cary Grant and Marilyn Monroe. New computer technology will make it possible to fully digitize these old stars, both visually and audibly, and place them in new environments and scenes. Imagine James Dean starring with Leonardo DiCaprio in a new Martin Scorcese movie. (look at the newest Tron trailer featuring a digitally-created younger Jeff Bridges - this gives you a taste of things to come)