From Scientific American about the science behind Microsoft project Natal:
But Peter Molyneux, creative director of Microsoft Game Studios Europe, looks forward to a new breed of computer entertainment, because eliminating game controllers opens up more creative possibilities. "Natal is forcing me as a designer to think of this as a relationship between the player and a piece of technology," he says. "We're trying to make something that feels as if it's alive."
As a player I will be really sad if my classic controller is out my games because is the way I enjoy and I really don't think I can relax staying in front of my TV moving all my body to dodge the bullets of my enemies.
But, as an researcher and a geek, I'm agreed with Molyneux. This will be a completely different way we can see the computing to interact with us to feel the machines are almost like another person that we interact everyday.
