“New wireless protocol, combined with the ability to work in ‘wired’ mode, and the addition of features like Impulse triggers, means that new software has to be written and optimized for the PC,” a Microsoft spokesperson told Venturebeat. “There is also some work that we need to do to make sure that existing PC games that support the Xbox 360 controller will work with the Xbox One controller."
A couple of months back, a rumor spread that PC drivers weren't coming to Xbox One controllers. "This is 100% wrong. When the drivers become available, they will work with the existing controllers. There is no plan to do a new, separate controller that only works on Windows. It will be the same as it is on Xbox 360 - the Xbox One controller you have today will work. That's not to say that we may not ship also PC SKU of the Xbox One controller, much like we do on Xbox 360." Albert Penello, Microsoft director of product planning replied.
Earlier this week, Hryb, director of Xbox programming, confirmed that Xbox One controllers will be compatible for PC users very soon. He did not mention a particular date or month though we are hoping it will be soon!