Well, that's a bummer: A Microsoft representative confirmed to Tom's Hardware that Windows Phone 8/8.1 users won't get the Windows 10 update until after the new year.
Windows Phone users -- those few and long suffering -- have been eagerly awaiting the impending update to Windows 10 for phones. In October, Microsoft promised that Windows 10 for phones would arrive in December, but that is not going to happen. (This was, by the way, after a rep told us at the time that the release date was November.)
Worse still, there is no specific timeline yet -- just "early" next year, which could mean as soon as CES (the first week of January), or as late as Build (the end of March). There is also still no definite list of Windows Phone 8/8.1 devices that will receive the update when it does come.
However, it's possible that providing the Windows 10 mobile update to existing Windows Phone users just isn't much of a priority for Microsoft -- and it would be hard to blame the company if that's the case. Windows Phone has a minute market share, and many of those users have been hanging on to their aging devices in anticipation of a new Windows Phone flagship device, which they just got with the launch of the Lumia 950 and 950 XL, which ship with a version of Windows 10 for phones.
Even low-enders are getting Windows 10 for phones with the Lumia 550. Most users stuck with Windows Phone 8.1 are actually more likely to be those who popped on the midrange Lumia 640 and 640 XL, which came out this year. Even so, the chief feature to entice anyone to the Windows mobile platform is Continuum, and that requires fairly high-end hardware, so it's not as if Lumia 640/640 XL users are missing out on the Continuum/Display Dock experience.
Microsoft may simply be making a calculation here, prioritizing other projects that need more attention at the expense of lower-priority ones, such as pushing out an update to a small (but dedicated, and increasingly impatient) cadre of users.