The 3D train has definitely left the station, but until recently if you wanted to hitch a ride on board, that meant purchasing a flat panel display. Now, flat panels have some inherent benefits for showing 3D, namely their scorchingly high light output which is incredibly beneficial for displaying 3D material. However, as wonderful as these flat panels are, they are unable to deliver a truly immersive 3D experience like the large screen of a two-piece projection system. Like the 3D that you experience at the theater. You know. When you saw Avatar in IMAX and this whole crazy really kicked into high gear.
Part of the difficulty of migrating to the projection world has been the light output issue. A theatrical presentation strives to achieve 12 - 14 foot lamberts at the screen for 2D presentations, and often produces far dimmer 4.5 - 6 foot lamberts for 3D presentations. The cost of doing business in the 3D world is losing more than 50% of your brightness.
At the CEDIA Expo, projector manufacturers are showing that while they might be a bit late to the party, they are in fact here and ready to party, and 3D front projection is one of the undeniable trends of the show.
I spent several trips walking back-and-forth along the long (and I do mean loooooong) black carpet running the entire center of the convention center, checking out the 3D demos and gathering the scoop and what's coming.