Despite all the talk of flatness—and there’s no question, the icons and certain other parts of the UI are much flatter—this gives iOS 7 as a whole a greater illusion of depth than it ever had before. The shadows and reflections of today pale in comparison. If Apple can enforce, or at least encourage, a consistent use of this new depth, our experience using iOS devices will improve because the software will seem even more physical.
I’m really interested to see if this bit of magic makes it to third-party apps or not. It’s a really neat effect that not only adds immense depth, but one that surprisingly makes the device feel a lot better to use — I’ve no clue why.