Google has just posted Android 4.4.4 factory images for several Nexus devices, following up seemingly randomly after the very publicized release of Android 4.4.3, which has recently just finished rolling out OTA. The images have just appeared on Google's Factory Image page, with no further announcement or information on what is included in the release.
The images carry build number KTU84P, and are available for the Nexus 4, Nexus 5, Nexus 7 (2012, 2013 and only for Wifi models) and Nexus 10. We're currently taking a look at them on our own devices to see if there are any noticeable changes. In the meantime, if you're so inclined you can have a download at the source link below and put them on your own Nexus of choice.