Why does this "concept" have such a specific thickness dimension? I guess the creator just shaved 0.4mm off and thought "yeah, they can probably do that."
Rear facing speakers? They need to go to front facing or continue with down-ward facing. Also stereo speakers, 20mm apart, have no benefit. I'd like to see grilles top and bottom, which, when you rotate for a landscape video, become left and right.
No home button. That's idiotic.
Bigger screen. Meh. I'm with apple on the idea that 4" is a good compromise of size and usability. I've got a galaxy s3 and an iphone 5 right here, and even if they had the same OS, I'd pick the 5 because I can reach all four corners of the screen with my thumb, one-handed, without changing hand position. The only reason I would want a bigger screen is if I had poor eyesight.
Nice 3d work I guess.