Microsoft's Chris Lewis has said that 3D gaming will take off when prices come down and the experience becomes more social (do you mean with Kinect, Chris?).
"We are two to three years away from that," he told Businessweek.
"'Til the price point comes down, 'til the experience is sufficiently social, that you don't sit there with big glasses on and don't talk to your family... That will happen, there's no doubt."
Lewis also talked about the Xbox 360 lifespan and how Kinect will give a boost to the console. It looks like we won't be seeing the Xbox 720 until 2015 at least:
"Kinect really gives us, I think, a very genuine additional five years," Lewis said.
"What Kinect does is broaden us out to users that we weren't addressing in the past."
Aaron Greenberg also put a five year life-span on the Microsoft motion sensor back in February.