Apple should really converge the ipad and macbook. Having something like a surface book where there's a laptop/desktop experience with a thin, light, detachable touchscreen and full desktop software would be really nice.
So far not even Apple has figured out how to make genuinely complex/feature-rich UIs (think Photoshop, XCode, Maya) work on a touchscreen device. Their best solution so far seems to be adding a keyboard and pointing device in the form of the Pencil.