According to Executive VP Devices and Studios at Microsoft, Julie Larson-Green, the company will no longer have three versions of Windows, but will unite all products under one umbrella



From WP Central:

Game engines are already starting to take advantage of how closely tied each version of Windows is. Now, during a Q&A held at the UBS Global Technology Summit, Larson-Green went into detail about how the company currently has all three versions of Windows, but this won't be the case in future:

"We do think there's a world where there is more mobile operating system that doesn't have the risks to battery life, or the risks to security. But, it also comes at the cost of flexibility. So we believe in that vision and that direction and we're continuing down that path."

  The future of Windows - Microsoft's devices head hints at further OS unification