Focusing on "low-hanging fruit" (things iOS' competitors already have or that are obviously missing) is important, but after a point Apple's going to need to break new ground and innovate.

Siri is a great example of this: iOS already ha voice control and nobody was complaining about it; it's just that nobody was really using it because it wasn't very good. Apple didn't get to where it is today just by cloning and refining things.