According to the Wall Street Journal, the upcoming “iPhone 8” will have a curved OLED display and will ditch the Lightning port for a USB-C port.
“Apple Inc. has decided to adopt a flexible display for one model of the new iPhone coming out this year and has ordered sufficient components to enable mass production, people familiar with the matter said,” according to the WSJ.
The article also says that reports that Apple will replace the Lightning connector with a USB-C port. All of the next iPhones are said to feature a "USB-C port for the power cord and other peripheral devices instead of the company's original Lightning connector,” according to the WSJ.
According to the Sellers Research Firm (that’s me) chances that the upcoming iPhone will have a curved screen are 80% (and it will be OLED, at least on a high-end model), but the chances are only 25% that USB-C will replace Lightning ports — at least this year. But I do expect this to happen in 2018.