Users of the Android Central forums posted screengrabs last night, and @fakeninjitsu on Twitter posted the above left photo. A quick straw poll of people I know with a Nexus 4 has not come up with any lucky updaters yet, however, and the rollout is likely to be staggered.
Google's Nexus 7 and 10 tablets , but many users complain they're still waiting for 4.4.
Nevertheless, the prequel to the Nexus 5 was the best value phone of last year by some margin and now looks set to benefit from Google's latest software tweaks, three weeks after the launch of the latest flagship.
While KitKat isn't a wholesale iOS 7-style overhaul of Android, it has some interesting changes. Every page of the interface has a search bar at the top, and Google Now gets a whole page to itself, to the left of the homescreen by default.
The dialler and contacts have had a serious reorganisation, with your most common contacts automatically prioritised. The texting app is gone, replaced by Hangouts, which can be confusing if you have more than one Google account.
If you've updated to KitKat recently, you'll find a whole bunch of useful tips and tricks right here:
Have you begun updating yet? Check your status in the comments, or on our frequently updated Facebook page.