Microsoft: all Lumias running Windows Phone 8 will be updated to Windows 10
The Windows 10 for phones was already in testing - with the Lumia 940 possibly being among the first handsets to run the OS (although, of course, at the moment we can’t confirm the existence of the 940).
We assume that most non-Lumia Windows Phone 8 handsets will also be updated to Windows 10. But that remains to be seen.
Windows 10 is a platform that will unify all Microsoft devices - PCs, laptops, tablets, smartphones, and even wearables. While it will look slightly different, depending on device type, it will be the same OS at its core.