I can see it now..
Please move your face further back it's too close.
Please move your face closer it's too far away.
All instead of - please press the home button.....
Yeah real innovation and moving tech forward!
Really can't see this being half as good as Touch ID. People will probably go back to pin codes!
Oh and as for the design, people do realise ever since the first iPhone it's ALWAYS had balanced chin on the top and bottom, the same size, one of the things I like about the iPhone actually, but this new design has removed that and you will now have the top chip bigger then the bottom which will feel weird when holding the phone in its side, it'll constantly look unbalanced when watching videos or playing games etc.
I hope they put a black bar on the bottom to even it out otherwise it'll look silly.