Interesting - the animation for the unlocking is somewhat similar to the animation when swiping between pages in the app list on Android Jellybean (I'm not criticizing the copying, just noting the similarity). Given the focus on layers in the rest of the design (the control panel and notifications center, for example) I would have thought the unlock screen would slide off like a layer, as well (since they are using the visual metaphor of dragging the whole unlock screen, rather than sliding a specific unlock element, as in previous version of iOS).

Any thoughts as to why they did that differently? Am I just totally off base?