Very cool, BUT...
If it is small enough to easily pocket, I see a potential MAJOR problem: DUST.
I was stupid (or ill-informed) enough to carry around my Canon S95 in my pocket for a long time, with no case. The camera is now useless, because over time, very fine pocket lint made its way into the inside of the lens.
If this new phone/camera is not extremely well sealed, the same might happen.