I expect smart glasses to be the next UI paradigm. Very conveniently portable. AR style visual interfaces. Built in speakers for personal audio (bose already do this in sunglasses). The AR interface could be directly manipulated by hand gestures using cameras and other sensors. I know there have been a couple of false starts (Google Glass) and current products with bigger form factors (Hololens), but I expect spectacles size devices with good UI in the not too distant future, and I look forward to the development opportunities.