This could be the point Nokia got to when the N95 got replaced with the N96 and nobody wanted it because it was crap.
If they do take out the headphone socket and replace it with either an expensive adapter or crappy beats headphones with a proprietary wireless protocol then many will see it as Apple pushing their luck just a little too far.
I know quite a few people with iphones that are sick to death with them and want to change to something else. This could be the one that forces them to move on. The main issues seem to be the fact they smash so easily and that itunes is still a dog and never works properly.
The greatest fear is that iphone owners will lose all their content if they move to another platform (which isn't true) but of course the walled garden is designed for that reason.
At least Samsung backed down when they removed SD support, and the issue with removable batteries was sort of dealt with by putting in higher capacity fixed ones. I don't think Apple will ever back down and will push on forcing their revenue generating crap and utter greed on users for as long as they'll take it.
10 years ago everyone had Nokia. Where are they now? Apple next .........