A recent report in Venture Beat noted that official upgrades to Windows 10 Mobile from Windows Phone 8.1 would begin later in March.

Now, a tip from a user running Windows Phone 8.1 on a Lumia 520 and joining the Insider program to go to Windows 10 Mobile shared with a new prompt before the upgrade.

What seems different is the upgrade notification looks to be a more official one denoting the Windows 10 Mobile update without the Insider qualifications. The prompt reads:

Windows 10 is here! Get hundreds of improved features, new Office apps that work seamlessly across your Windows 10 devices, and more. For details about how the update will impact your experience, please read windows.com/mobilespecs. Significant download required.

Granted, it has been a long time since we updated a Windows Phone 8.1 OS to Windows 10 Mobile, so we'll leave room here for 'this is just old news'. However, that message does seem like the one a Windows Phone 8.1 user would get who is not on the Insider program.

Windows 10 Mobile build 10586.122 did seem very stable on our numerous test devices and the new changelog for build .164 reveals even more refinements and fixes. The timing of the release and Venture Beat's report seem to align properly as well making this .164 release one of the final ones for the Windows 10 Mobile rollout.

Also, since this update is going to all non-carrier phones that shipped with Windows 10 Mobile e.g. Lumia 550, 650, 950, 950 XL, Coship Moly X1, and Nuans NEO, and others it does appear rather final.

Microsoft mentioned at the end of February that certain older 8.1 phones would also get new firmware where it was needed to fix any compatibility problems with Windows 10 Mobile. Otherwise, the Windows 10 Mobile is only a software release.

We'll have to wait and see what Microsoft plans to do by the end of the month. There is also the carrier factor, which will likely play a role in delaying updates for branded devices as well.

What do you think – Is Windows 10 Mobile build .164 finally ready for prime time?

Thanks, @siddharthabera9, for the screenshots