There have been numerous rumors over the past several months suggesting that Apple was working out a deal with Samsung Display Technologies. The rumors indicated that the Korean manufacturer would be building OLED display panels for some future Apple device. Most of the rumors pegged 2018 for the first year we would see an iPhone using Samsung's OLED display tech. Today's intel suggests that time-table has been pushed forward to 2017.
The news is that Apple and Samsung just inked a deal worth $2.59 Billion USD for Samsung to make 100 Million OLED display panels for Apple in 2017. It looks like it won't be an exclusive deal, but Samsung will get the vast bulk of the order. Companies like LG Display, AU Optronics and others will source additional panels either for overflow or for select markets.
The main reasons cited that Apple plans to go to their biggest competitor for the majority of their future iPhone displays is because OLED panels will help Apple reduce the thickness of their devices and the bezels of the displays. That's because OLEDs don't use the same backlighting technology found in traditional LCD display tech. The other advantage of OLED's is that they have brighter colors and typically provide sharper images.
The only disadvantage of OLED tech in the past was that it was more expensive to produce. Samsung has basically erased that disadvantage by continuously investing in OLED tech. In fact, some reports have indicated that Samsung plans to invest up to $7.47 Billion in advancing mass production for OLED displays. If this contract with Apple turns out to be true, then it looks like Samsung's bet will have paid off.