You cannot expect to have the latest and great anything when you sign a two year contract in an industry that turns over its product line every 12 months.
As an AAPL shareholder, I will be livid if they don't offer an upgrade in about a year. As an iPhone user, I'll happily figure out a way to upgrade for little cost by negotiating credits from my carrier, and by selling my old iPhones on the open market ASAP after the new iPhone is in hand. Of course, that assumes the 4S to 5 changes will be worth it. The addition of Siri alone, not to mention a better still camera and 1080p video, made the recent upgrade a must have IMHO.