I got the update on Saturday (12/20/14) for my Lumia 822. It was a two-step process. First upgrade to an interim version of Windows 8.0, then upgrade again to Windows 8.1, Update 1.
Both upgrades to quite a bit of time. About 90 minutes for the upgrade to the interim version of Windows 8.0, then two plus HOURS to upgrade to Windows 8.1, Update 1. (Not sure the exact time, since after the two hours mark I left home and came back 6 hours later to find my Lumia 822 was successfully upgraded to Windows Phone 8.1, Update 1.