Also maybe consider dropping:

> App state is saved when stopping the app and restored on next start

I believe you get this for 'free' with IOS 4 and greater, as the app now never stops, it just suspends to the background when you switch between apps.

Not if the device runs out of memory or on older iOSes. You should always address this case.

I didn't consider out of memory condition, thank you. I wasn't worried about older OS as practically speaking there are not that many folks on IOS 3 or older, at least based on stats I've seen for iPhone. I don't specifically target iPods, so maybe there are more of those at 3 vs iPhone. Thanks again - great list!

Even on iOS 4, the iPhone 3G doesn't support multitasking.

Good point - I seem to have forgotten that as well as I considered 3GS or greater to be my target. So it is a good point to consider for usability, depending on the app. But FYI, at least in my app's case, it wasn't a determining criteria or test in order to pass app store review.