i'm disappointed that we haven't made more progress with voice interfaces. Many people are happy with the keyboard/mouse as their primary input devices but combined with subtle gestures like you might get with Google's Soli and we should get a better user interface for everyone.
Good trackpads/touchpads with gestures aren't that far away from Soli, once you accept that people are lazy and don't want to fight gravity with their hands.
http://www.youtube.com/watch?v=0QNiZfSsPc0