Maybe pico projectors got really good? And I am not sure about edited demo, maybe partial but why would they make the projection lowres and stuttery.
It's obviously intended to give a realistic impression on how a final implementation would look. But there's no way this video wasn't edited.
But the problem, as I said before, isn't the possibility of implementing such a technology but in marketing and selling it. Pico projectors mounted behind the TV won't be able to achieve an effect as shown in the video. This may be interesting to some, but necessitates people spending quite a bit of extra money and jumping a pretty steep setup hurdle for a nice, but not critical, effect.
I'm pretty sceptical of this ever being a real product.
If it's part of a wireless Kinect 2, probably a lot of people.
This would still mean you need a suitable place to install a projector - something that is pretty hard to come by in most homes without doing any additional works done by a handyman.