Microsoft is facing a marketplace in two years where they can extend Win7 in hopes they can eventually have an OS that they think will appeal to folks who refused their gargantuan push of a few years ago, or they will go "All-In" and attempt to force users to join the Win10 borg.
They have effectively lost the commodity server space to Linux (look at what the majority of web services runs on), and the Apple generations continue to skip Windows, so they aren't winning in the desktop space. In fact, desktops are losing to mobile devices (Android and iPhone).
For many practices performance would go up and costs go down by going to terminal services and a mix of desktops (Mac, Linux) and mobile devices (Chromebooks, Android, iPhone). Your one Windows OS necessary would be the server, and MS is much less willing to drive their remaining server clients away with the kind of tone-deaf behavior that continues to alleniate the erstwhile Win10 desktop users.
