Use of this seventh CPU by developers could lead to additional performance improvements on the Xbox One, but right now this is going to be difficult because of a lack of scheduling that allows for monitoring of the CPU to be able to better anticipate the time slices of the CPU that are available for use.

Microsoft intends to work on the Xbox One OS in the future to better address the short comings of the task scheduler which will of course lead to better performance once completed. It still remains a mystery how much developers will be able to gain from leveraging the power of access to this additional core, but again it is another path that Microsoft is offering developers in order to improve the performance of their code on the Xbox One.

It is bit technical, but you can check out more details over at Eurogamer.net.