I just hope that Apple does not do what other phone manufactures have been known to do and that's release two variants of the same generation phone with differing specs.
For example, releasing the 4.7' with a better camera than the 5.5' but with less storage than the 5.5', that would be terrible as I would then be forced into a difficult decision. Do I want the better camera or do I want more storage? The fact is, I want (need) both.
Apple should either make both variants with the same specs, save for the bigger screen of the 5.5 and bigger battery to accommodate the bigger screen, or they make one variant so much better than the other that it is clearly the flagship device while the other is seen as the budget option ala the 5c.
Knowing Apple, it won't do such a thing but never say never.