I would love to see dramatic changes to iOS. But I don't expect them. At most, I expect a new notification system and a couple of other tweaks.

The last time Apple made a really big dramatic change to this type of (existing) software was moving from Mac OS 9 to Mac OS X. That's the kind of change I'd like to see in iOS frankly. At least on the superficial level (UI, apps and maybe a few frameworks) But I don't expect it will ever happen. Even though there are enough areas open to improvement that could substantiate a major overhaul.