"Windows 10 is the last version of Windows”, says Microsoft

At Microsoft’s Ignite conference, Microsoft employee and developer evangelist Jerry Nixon said that “Right now we’re releasing Windows 10, and because Windows 10 is the last version of Windows, we’re all still working on Windows 10.” 

That sounds like Microsoft won’t be releasing any more versions of Windows 10, which is true more or less.

Windows Phone 8.1 review: Major league

Windows Phone is yet to become the game changer Microsoft wants
it to be. It didn't quite experience the kind of explosive growth that
could've put Nokia back in pole position, but it has been steadily
climbing up the ranks. Maybe an upgrade of the scale of its 8.1
version is all it needed to go into overdrive and really challenge the
big two in the smartphone game.

Nokia-Microsoft deal now officially done

It's done – Nokia has just announced the completion of the sale to
Microsoft of "substantially" all of its Devices & Services business to
Microsoft. "Substantially" since two factories were excluded from the
deal – the Chennai factory in India , but also the Masan factory in
South Korea.