First, a comment from John Gruber:
"Apple’s strategy for lower-priced phones for the last four years has been to sell one- and two-year-old models at a discount. But perhaps the glass-backed iPhone 4 and 4S (and, come next year, the aluminum-backed iPhone 5) are inherently too expensive to produce to hit certain lower price points. Maybe Apple just wants to get rid of the last remaining products using those old grody 30-pin adapter ports. But whatever the reason, this would be a significant strategic shift."
Selling the previous two years models to address the lower end market may have worked in 2009 or 2010 but today, this strategy is showing sign of inadequacy against the proliferation of cheap Androïd devices.
I have the feeling that the iPhone 4 or 4S aren’t that cheap to produce even after two years of mass production. Creating an updated design with cheap components and cheap manufacturing needs will not only help protect current margins but would help keep the iPhone line fresh from the top to bottom. People like “new” things in new cases, new colors and new textures even if internal components aren’t state of the art.
A fresh iPhone entirely new and designed for the low end is mandatory. And only Apple can creating something great without falling in the trap of all cheap Androïd plastic devices. Not sure about this? I invite you to consider the just released iPad mini.