For those not willing to wait for the OTA from 4.3 to 4.4 KitKat, you can download the update now!
Our friends over at XDA found the manual installation URLs. One goes from 4.3 JellyBean (JWR66Y) to 4.4 KitKat (KRT16S). The other goes from 4.4 KitKat (KRT16O) to the 4.4 bugfix OTA (KRT16S). It’s easy to install! Just place the zip in your ADB folder and sideload it like you normally would.
Enjoy your KitKat!
4.3 (JWR66Y) to 4.4 (KRT16S) – Download
4.4 (KRT16O) to 4.4 (KRT16S) – Download
Source: XDA

About Derek Lockovich
I work in Network Services. I love music and play a little guitar. Android is my favorite mobile OS, and it always will be as long as Google keeps pushing out fantastic products. The Nexus 4 is my smartphone and will soon be upgraded to a Nexus 5.