The dream doesn't seem far off with Apple's recent patent for a pico projector on their mobile devices, but the question is if the technology is there yet. We have seen laser keyboards existing for a couple of years now, but sadly they were never a true solution for everyone due to their lack of precision.
Probably my biggest question would be if you'd really end up using it as much as we know people don't really care much about FaceTime. There are certain things that simply don't reach that much importance if not well executed. In the case of FaceTime, people don't really use it much because of how limited you are to Wi-Fi. The same case would happen here if the Pico Projector doesn't bring any significant improvement to the way you experience content on the phone.
I've gotta hand it to these guys though. Even if this is a dream at the moment, I'm really impressed by the quality of this video and how they were able to pull this iPhone 5 concept off.