To honor the 10th Anniversary of the iPhone, Apple are to release 3 new iPhones this year. The two current models will be refreshed, featuring updates, while a brand new flagship phone will be released. It is said the new flagship phone will be to expensive for most people to purchase.
For the premium model of the phone, the screen will be like the S8 and cover almost all of the front of the device. The display itself will also be an OLED display made by Samsung. Also, for the premium model, the home button will be removed, and will be accessible via software. This is to decrease the overall footprint of the device. The camera components used will be from Sony, and may be placed vertically instead of horizontally.
Basically everything I said above came from Bloomberg's article here:
There is a load of information on past and current prototypes in that article.