Just over a week ago I ran the numbers on a bigger screen iPhone, and presented several ways Apple could go, including just taking the current screen and stretching it out to almost 5-inches, which would give it the same 264ppi pixel density as the Retina iPad 4 screen. Since Apple used the iPhone density to make the iPad mini, using the iPad density to make the iPhone maxi has a certain symmetry to it.
But would stretching out the icons, buttons, text and other interface elements just make them look bigger, or would it make them look silly? Let's find out...