Apple’s long-term roadmap here is to allow users to create 3D images for the Mixed Reality headset. Apple might also allow users to virtually draw in 3D space. The images will be created in free space by the motion of the Apple Pencil and will be captured by the Mixed Reality headset.
Furthermore, Apple is also planning to let developers use Apple Pencil to map movements for other apps as well. This can include apps as well as games where Apple Pencil will act as an input device. We still don’t have an estimate on when this feature will be shown to the public but we expect it to be sometime in 2019.