I'm not on-board with your XP comment, but I do agree that we have in many ways reached a point where increasing numbers of people that would upgrade phones constantly no longer feel the need to do so.
I'm in that category. Next month I'll have kept a phone for 2 years. I can't recall when that last happened. The same goes for my other 2 mobiles - I see zero reason to change any of them... at all.