Are you disappointed that after sixteen months, Apple followed the iPhone 4 not with a radically redesigned iPhone 5, but a mere iPhone 4S?
You shouldn’t be. There’s a reason the iPhone 4S is just a slightly better iPhone 4, and it’s because Apple’s looking out for you.
That’s also the reason you should expect an iPhone 5S, iPhone 6S and iPhone 7S every two years, like clockwork.