[Update: Microsoft has reached out to Destructoid to note that simply unplugging your Kinect will not increase your performance. It's solely based around the fact that developers can now program without the Kinect requirement in mind.
Here is the official statement: "For titles that ship in the future, if a developer has taken advantage of this SDK change they may access this additional GPU resource. We have started working with a number of developers on how they can best take advantage of these changes, and we’ll have more to share in the future."]
The mystery is over as to why the Xbox One version of [insert game here] is typically inferior resolution-wise to the PS4 version -- the Kinect requirement ate up 10% of the GPU performance, according to a statement given to Eurogamer by Microsoft.
Now that the Xbox One is launching a Kinect-less version developers will be free to hit higher benchmarks, which may or may not include higher resolution and fps rates. Commenting on the issue a Microsoft spokesperson stated, "Yes, the additional resources allow access to up to 10 per cent additional GPU performance. We're committed to giving developers new tools and flexibility to make their Xbox One games even better by giving them the option to use the GPU reserve in whatever way is best for them and their games."
This no doubt played into Microsoft's decision to drop the Kinect requirement -- both developers and consumers alike were clamoring for it.
Xbox One dev kits receive more GPU bandwidth [Eurogamer]