A couple more nice to haves in iOS 6:
Multi user support - I've seen many people use their iPads both for work stuff like email and then handing it over to the kids once they get home, so the little ones won't bother mommy while she's busy with the brandy. Or perhaps someone is using their iPad both for private stuff and want's to use it to play music at a party where all their friends are going to use it to pick tracks. In both cases some sort of user discrimination would be advantageous.
Allowance for 3rd party apps that replicate Apple app functionality - Personally I think Apple's apps are just fine, but I acknowledge that other users might think differently. Case in point;
Ars' review of Sparrow for iOS. This app could have been a lot better if Apple wasn't guarding Mail's privileged position so jealously. Sure this will add some confusion, but as the iOS platform matures, I think more users will begin to ask themselves why they are forced to use Safari as their only browser.