KitGuru has reported that Microsoft is going to introduce a white Xbox One later this year. Whether it will be available as a standalone option is unclear. However, the white variant will be available in the future paired with the game Sunset Overdrive, a third person shooter developed by Insomniac games. It looks like the Kinect sensor will not be included in this bundle.
The white Xbox One (with Sunset Overdrive and without the Kinect sensor) will be available for $399. It's known at this point when this bundle will be available, although we do know that Sunset Overdrive will be available on October 28.
KitGuru predicts that a white version of the Xbox One will make it slightly more popular, but that it won't help sales by much. There is a rumor on the web that Microsoft will be announcing a $50 / €50 price cut at Gamescom 2014 for the standalone Xbox One. Unfortunately, TechRadar was told that the original listing was an erroneous posting, and that Microsoft has no plans to cut the price. This seems like a fairly typical response, as Microsoft would be cannibalizing a lot of its sales if the public were to figure out that there is a price cut right around the corner, so let's not dismiss this one just yet.