Microsoft's hypervisor is capable of offering dynamically allocated resources. There was a discussion of this quite some time ago when it was first revealed that the Xbox One would be split between 3GB and 5GB.
With the Hypervisor OS capable of scaling resources available to one or the other and having hard stop limits, it means that you could allow the Apps VM to scale lower than the 3GB hard limit, and the Games VM to scale larger than the 5GB.
And despite what people think (i.e. believe) you can have an application that scales to available memory. Microsoft SQL Server does this today. SQL Server consumes 100% of available physical memory and then relinquishes it as the systems needs change. Open up the event viewer on a SQL Server server, and the SQL Server has that much less memory to use.
The Apps VM may not use anywhere near the 3GB of memory, and CPU and GPU cores assigned to it when a game is running full screen. I don't think Kinect is a target, just he's pointing out that 10% of the GPU resources are assigned to Kinect when a game may not be utilizing any functionality where the GPU is necessary (i.e. they support voice commands).







