2012-13 at the earliest, but I really can't see them doing that. The future belongs to touch but even more so gesture, thats for certain. Getting there will take a little longer than we anticipate. I do not actually see us ever touching our iMacs. I think apple will jump to gesture for larger screen/device interactions. Look what the Wii, PS3 Move and (gasp) Microsoft is doing with Kinect and there motion control technologies. Everyone is chipping away at a gesture controlled future (Microsoft being the closest), it's a matter of time and we can skip right over the potential greasy iMac scenario.I'm sure when teh tech matures enough Apple will buy up some Gesture startup and integrate it into everything they can when they feel the market needs it.