The big question, however, is whether Apple will choose to release a full upgrade (like the iPhone 3, 4 or 5) or simply enhance the existing model (similar to the iPhone 3GS and 4S).
Apple has been known to release a major upgrade every couple of years and do minor updates in the in-between ones. 2013 is slated to be one of those minor upgrades year, giving competitors a chance to come out with something mind-blowing.