It's looking more likely that this year's iPhone will be "left in the dust" by next year's iPhone. We'll know for sure in 5 months if it actually looks like those leaked photos. Then a major redesign next year becomes more likely in my opinion.
I had not considered the fact that this would mean the iPhone '7s' or whatever they choose to call it, could make the iPhone 7 look outdated and old. Now I have an even greater argument with myself in September as to whether I keep my 6 Plus for a third year in hopes that these rumours about the 2017 model are true. I'm not really one to 'wait around' in the hopes a new model comes, cause a new model is always around the corner. But I'd quite like a glass iPhone back, loved the 4.