I love the iphone, but if apple wants to be the best and sell phones at a higher price point then the competition they need to make it worth the purchase.
With the removal of the headphone jack and a slight re design it will not help matters either.
The New iphone needs to have a better oled display, better battery life, better anodizing with darker space gray and a more appealing silver etc., better size options 32,64,128gb, stronger glass, and waterproofing, lastly a smaller bezel with the same size display.
They also need to take the SE, 6s, 6S+ and make them all 7's with 4", 4.7" 5.5" displays. They will have some differences like battery life probably, but they need to all have the same specs and features.
Now the new phones wouldn't need this all in the next upgrade, but they would need to implement most of this over the next couple years.
Then you take software and we have a whole new ballgame. This needs a big update in ios10 with new features like seen in other articles on macrumors. While improving reliability and software related issues.