I have a theory that the accelerometer-linked 3D "layer" effects might make the flat interface more usable in person. As in, the subtle perspective shift would make it obvious that a button is a button, etc. Can you comment on that? Are those effects extended to all of the UI elements?
It seems like a pretty gimmicky effect right now, although if you hold it in a certain way it does have a cool 3D effect. The scrolling animation stutters quite a bit currently. I anticipate they'll have that fixed by release.
They aren't, and even the little layer effect on the home screen is nothing but a gimmick. I don't wave around with my phone while I use it and would never have noticed the iOS6 volume slider effect if blogs hadn't pointed it out.