All are good recommendations, but, as I have alluded to before, I also think that iOS 6 should be the “Snow Leopard” of iOS releases, speeding up the inefficient areas of iOS as it currently stands (Notification Center, multitasking, homescreen editing).
I also feel the Home button usage needs to be improved. Not only is it frustrating to constantly double-tap the home button, or triple-tap it, or long-hold it (I mean seriously - think about it, it’s just too much), it also represents poor UEX. It’s unintuitive. It is not obvious that you should double tap to bring up the multi-tasking tray. Why can’t you swipe up from the bottom of the screen? You can swipe down from the top and bring down Notification Center, after all.
Speaking of which, Notification Center has a poor UI metaphor. The linen texture is used throughout iOS to show things under the Springboard, except with Notification Center, which appears over the Springboard. It would be a minor tweak, but a huge UEX/UI boon, if Apple made Notification Center’s UI appear to “push down” the Springboard (or open app), just as the multi-tasking tray appears to “push up” content.
I feel there are a lot of tweaks that could be made, but I don’t claim to have the solution (I’ll be thinking about it over the coming weeks). The Lock Screen is a prime example - it has lost its “Zen” simplicity and symmetry with the addition of the Camera icon, but the convenience gain outweighs the aesthetic loss. Perhaps it should be re-thought entirely?
Things are beginning to feel cluttered and/or tacked on with iOS and I find myself wanting “room to breathe”, ranging from literally wanting more “free” space between objects in the UI, to thinking that UI metaphors need to be rethought.