The Wii was the most recent commercially successful step that consumers saw in the evolution of the human-computer interface. It felt pretty revolutionary--it used natural human motions instead of adapting our motions to the interface. But it was definitely a step in the right direction.
Some of the interfaces displayed at Siggraph this month show amazing potential to revolutionize input all over again. We have touchable holography (there is still a long way to go until we reach holodeck levels), augmented reality, hyper-realistic virtual reality, 3D teleconferencing, and scratchable input. Just wait until they start releasing scents with that last one--it'd be the best scratch-n-sniff ever.