|iOS 6 on left, iOS 7 on right|
I am pretty surprised by this pretty major change in iOS. This seems like pretty basic functionality that has been changed. I know that a lot of it is because of the new UI paradigm that Apple is trying to introduce, but this seems like quite a major change in implementation from previous versions. What this seems to me is that every app developer is now going to have to be extremely careful about this upgrade and what it means to their apps.
Good luck with your apps.