"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
Apple Seeking Software Engineer for Future User Interfaces
HID SW is responsible for delivering the firmware and software for Apples Input Devices, such as Multi-touch for iPhone, cameras, and remote controls. The team is a key part in driving an integrated customer experience involving new HW and SW designs, working with creative, smart people, world-class products and cutting edge technologies.
Of course, the job description is understandably vague, but does seek out applicants specifically with "strong interest in human-computer interaction" and "a proven ability to bring new user interface concepts to life". The reference to cameras and remote controls, however, raise some interesting possibilities.
After the introduction of the multi-touch iPhone and a series of patent applications exploring alternative input methods, it seems that Apple has been paying a lot of attention to the future of user interfaces. Many of the recent patent applications focus on advanced gesturing and unique touch surfaces.
There's been some suggestion that the upcoming sub-notebooks might see some touchpad improvements, though this has been particularly vague.