Windows 10 Mobile Beams To Select Devices With At Least 8GB Internal Storage In December
In response to a question posted on Facebook, Microsoft stated that "broad availability of Windows 10 on other devices" than the Lumia 950 and Lumia 950 XL, "including mobile phones, will begin rolling out in December." In other words, Microsoft is wrapping up work on Windows 10 Mobile and will put on a bow on it by the end of the year -- Merry Christmas, happy Hanukkah, and so forth.
If that's true -- and Microsoft has previously stated that Windows 10 Mobile will arrive by the end of the year -- then you can probably expect a Release to Manufacturing (RTM) of Windows 10 Mobile within the next month. That would give carriers a few weeks to test the polished code for any lingering bugs before its official release.
Bear in mind that Windows 10 Mobile's launch doesn't necessarily mean widespread availability. Microsoft may decide to start with just a few handsets to see how things go. In addition, some devices may get left off the list, such as the Lumia 530, which doesn't have the necessary 8GB of RAM.