Steve Jobs wanted iPhone 5 rather than just an iPhone 4S. Overworked Apple employees resisted and there was mutiny. Instead of the Apple board throwing him out again, they gave him the option of stepping down.
Shareholders were getting increasingly unhappy about the costly short upgrade cycles and the money spend on research to get new models of the popular products. They could as well milk the product until consumers no longer would buy it while slowly bringing newer models. It would be more profitable to bring a minor update every 15 to 18 months.
iPhone 4S is in that right direction. Apple knows one thing, that they couldn’t call it iPhone 5 and they are right about it. Only geeks could recognize the value went in. For most consumers, it looks like iPhone 4 and it is just iPhone 4. It just got faster. May be a better camera. They would buy it anyway.
The only people who will hold off buying the 4S would be the ones that are looking for a different look or form factor or whatever you call it. Then when the withdrawal kicks in, they will fall in line too.