The next 5 years are going to be very interesting for Apple. With their mind-set, I'm not sure where they can go with the iPhone from here. They're obviously not interested in changing the OS and I doubt they'll ever go with a larger screen. They've kind of painted themselves into a corner.
Just my 2 cents, but I have this feeling that Apple will be reduced to dust by 2025 should the slow rate of innovation in the iOS component continue, given that it powers 2 of their most popular products: iPhone and iPad.