Turn around is fair play: #boycottandroid #iphone5
Since I bought my first iPhone, I've known that I would get OS upgrade support for at least three years. By that time the hardware is so out of date that it is really time for a handset upgrade.
That said, no other phone that I've ever owned has ever had an OS update. Most handset makers take a shotgun approach: make a bunch of devices that are very similar but with some overlapping and non-overlapping features, get people to buy them, and then forget about them. There has never been any long-term support. iPhones may not have all of the latest features, whistles, and bells, but at least they have good support from Apple.