And what of the parallax effect? It is actually very tricky because it goes against what you would expect to see from the "layers". If anything, the icons should move in the opposite direction (towards the edge that remains closer to you) to maintain perspective. In other words, having the icons move to the right when you tilt your phone to the right is backwards... If they moved left, they would appear to remain in line with the background.
Anyways, say what you will of Forstall. At least his notifications didn't go on a huge spiel about the weather without telling you the temperature, or going on about your events without telling you anything about them
If it weren't for his thoughts and designs, iOS might not have caught on as well as it did.