Microsoft is putting a lot of faith into the success of the Kinect accessory for the Xbox 360. Reports are saying that Microsoft is requiring support of the motion and voice sensing device for all future Xbox 360 applications. It does not require that it actually have to use the Kinect as a sensor or controller, but it needs to support it (either voice, gestures or both). I wish Sega would have supported their add on devices on their hardware back in the day!
Microsoft is putting in a lot of time and effort into making the Kinect and the Xbox 360 a success. Given that they have released the SDK and plans for a PC version, and the mandatory support for 360 titles show that they are in it for the long term. Perhaps the successor to the Xbox 360 will have an integrated next generation Kinect sensor built in. Time will tell.