Don Coyner, the man who led the design of the original Xbox and the Xbox 360 has been replaced as the design of the next Xbox started.
Don Coyner is the General Manager of Entertainment Design at Microsoft and he hasn't been fired, but it has been confirmed by two sources inside Microsoft that he won't lead the design of the new console like he did with the first two. Apparently Coyner has been replaced by Emma Williams, a fellow General Manager at Microsoft. Emma was involved with the creation of the new Xbox 360 dashboard which was released earlier this month.
This personal change might aim only to bring new ideas and creativity to the design, but it seems to us that the main reason is to have the new console experience revolve more around "natural interface" through kinect.