According to news Microsoft to merge all its major versions of Windows into one huge Windows platform.
According to Nadella We will streamline the next version of Windows from three operating systems into one single converged operating system for screens of all sizes. In the past we had multiple teams working on different versions of Windows. Now we have one team with a common architecture. This allows us to scale, create Universal Windows Apps.
Microsoft is following Apple's approach, Apple has two app eco-systems: iOS (mobile products, iPhone and iPad) and Mac OS (PC products, MacBook laptops, iMac desktop).
But Microsoft will still sell different editions of its operating systems, for instance, a Windows Pro edition, a Windows Enterprise edition, a cheap one tightly bound with Bing for low-price devices. But under the hood, they will be more alike than different.