It appears 3D touch and multi-touch functionalities weren't enough for Apple. In fact, it was revealed today that Apple has been granted a patent for touch-free gesture input. The patent abstract suggests that the technology could theoretically allow you to control your Apple devices by hovering your hands over their displays, keyboards, and trackpads.
While that feature seems like the sort of gimmick most users would abandon after calibration, the patent also suggests the use of similar sensors designed to prevent accidental touch input on your iPhone screen. This could be useful in the case of talking on the phone, or perhaps even listening to music on YouTube while it's in your pocket. The iPhone already attempts to reject touch input when it thinks you're speaking, based on input from its internal sensors, but the new patent suggests a more refined system could be in the works.
Seeing the term "gesture controls" may instinctively lead you to draw connections to Microsoft's Kinect, which has all but bit the dust at this point. This patent, however, appears to suggest more close-range "hover event" detection rather than living room party game banter.
Moreover, the patent explains that although some functions could be initiated by gestures alone, others will require both touch and gesture input at the same time. In turn, this could indicate an evolution of multi-touch as we currently know it.
Apple also makes it seem as though the proximity sensors responsible for the repeatedly aforementioned gesture controls will exhibit the same amount of pixel-level coverage as the touch sensors before them, though it's also possible the displays themselves could intersperse between touch sensor rows and rows which detect input proximity. Otherwise, it's also possible we could see proximity detection only occupying a carefully selected portion of the screen.
Oddly enough, the patent goes in some detail on more than just iPhones and iPads. In fact, it specifically mentions the use of proximity detectors for virtual keyboard emulation from the surface of a trackpad. It also mentions such technology could be used to supersede current iPhone proximity detectors.
Nonetheless, everything mentioned here should be taken with several spoonfuls of salt. Most patents from companies of Apple's stature don't make their way into manufacturing. Still, Apple did demonstrate an extensive interest in gesture inputs as far back as 2013, when it purchased the company behind the original Kinect.