About that, there now seems no doubt. Speaking to CVG at Gamescom, Microsoft corporate vice president Phil Harrison explained how the Xbox and Kinect are fundamentally two parts of a single entity:
Xbox One is Kinect. They are not separate systems. An Xbox One has chips, it has memory, it has Blu-ray, it has Kinect, it has a controller. These are all part of the platform ecosystem.
Initially, Microsoft claimed every Xbox One would not just ship with a Kinect, but that it would have to be plugged in for the machine to run. Then, it stated that the second part would no longer be the case, raising fears that the console might not ship with the sensor. That would—could—have allowed Microsoft to ship a cheaper version of the Xbox One, but it had developers worried about making assumptions about hardware.
Now, it seems we know for sure: there won't be a cheaper Xbox One option, you will get a Kinect when you buy one—and your gaming experience will probably be the better for it. [CVG via Polygon via Verge]