M$'s goal has always been the change the battlefield landscape, from hardware refresh to software refresh...Natal will extend this generation another 1 or 2...so I expect a new console launch in 3 years, but the old console will continue on for many more after that, but I suspeect M$ plan the next console as nothing more than a glorfied refresh of tech, thus allowing developers to not miss a beat in programming from console to console.