Resident Evil and Vanquish creator Shinji Mikami doesn't think hardcore gamers will warm to motion controls until they can follow your eyes around the room.
With imminent release of Sony's Move and Microsoft's Kinect, motion controls is a rather hot topic at the moment. Some developers, like Peter Molyneux or Greg Zeschuk, see a lot of potential in the technologies, but Mikami believes that motion controls need more development before they become "mainstream."
By his estimation, it will be more than ten years before motion controls are really accepted, and they will need to be much more sensitive before they will really be able to replace a controller. "When the technology gets to the point where you can just flick your eyeballs around and the computer can pick it up, you won't need a controller anymore," he said. "Obviously it's going to take a while to get there."
Presumably, when Mikami says "mainstream" he's referring to "mainstream hardcore gamers," as the Wii is enjoying a great deal of mainstream success. Ten years seems an awfully long time for people to get used to motion contols - that would be a significant way into the next console generation - but it definitely will take time, something that even supporters of motion controls have suggested.