As you can expect, Nexus devices are the first to get the Android 4.4.4 (KTU84P). Google has already published the factory images and binaries for the Android 4.4.4 firmware of Nexus 5, Nexus 4, Nexus 7 (both), and Nexus 10 on its developer site.
The over-the-air update has also started rolling out for Nexus 5 and we expect it to go live for other Nexus and Google Play edition devices in the coming days. The Nexus 5 Android 4.4.4 update is just 2.5MB in size and can be downloaded for the manual installation from here, after downloading the update, you can follow this guide to update your Nexus 5 using ADB Sideload.
