"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
New Multi-Core iPhone with Firmware 3.0?
Meanwhile, Imagination Technologies is announcing a multi-core GPU that could be suitable for iPhone use. Apple, an investor in Imagination Technologies, presently uses a less powerful version of their PowerVR GPU in the iPhone and iPod touch.
The likely candidate for the new iPhone's CPU, however, is a derivative of the ARM Cortex A9 multi-core processor. The ARM Cortex has excellent power efficiency, well ahead of Intel's Atom offerings. Apple appears to be an ARM architectural licensee and their acquisition of P.A. Semi has brought low-power chip design expertise into the company.