I feel that recognisable and consistent tactile feedback is so important for developing and executing muscle memory. Today on most devices this element is largely overlooked (eg. compare a walkman with physical buttons to an music application on a flat screen surface).

Touch screen devices with vibration hardware have not really addressed the haptic positioning and behaviour of tactile feedback.

All of this to me is a loss of opportunity to exercise an additional "input method".

In the future I expect to see somewhat of a non-flat screen that's able to reposition the height or texture of its area to facilitate the do-not-have-to-look precision requirements of today's on-screen buttons. Somewhat of a 3D holographic surface which you can touch or otherwise feel.