With all the rumours about the iPhone 7S and iPhone 8 one thing that has been missing is talk of a replacement for the iPhone SE, Apple's best selling iPhone in many territories.
The SE wins by virtue of its industrial design and smaller screen. It's far superior in the hand and much more portable than larger iPhones. The hardware design is the archetype for an iPhone, having been used since the launch of the iPhone 5.
In some ways this makes Apple's job of replacing the SE very easy. It need only take the guts of the iPhone 7 and fit it into the existing chassis. Shouldn't be too challenging.
The only concern might be adding the 3D Touch feature on a new screen size and, personally, I can absolutely live without that feature.
My big concern is the new Touch ID sensor, which does away with the home button and introduces a solid state click free sensor. I hate it. It would definitely prevent me from upgrading to a new iPhone SE were it to be included.
The SE is far and away the best iPhone. Hopefully Apple will be careful to retain the features which make it popular with customers when time comes to update it.