Previously, Microsoft had said the rollout would begin this month, but there are some delays it appears.
Says the company: "This November we introduced Windows 10 to phones including brand new features such as Continuum and Universal Windows Apps with the introduction of the Lumia 950 and 950 XL. The Windows 10 Mobile upgrade will begin rolling out early next year to select existing Windows 8 and 8.1 phones."
It remains unclear which existing Windows Phones will get the upgrade and which will not although if you purchased in the last year you are likely to have an upgradeable phone.
Source:
ZDnet
Written by: Andre Yoskowitz @ 19 Dec 2015 15:33