The code is split in two branches, kitkat-dev and kitkat-release. Build number being KRT16M, which is the release version on the Nexus 5 at the moment. They also mention that the binaries and factory images should be up later this evening as well.
To top off your tanks, the Nexus 4, Nexus 7 and Nexus 10 updates to KitKat are mentioned for update rollouts in the next couple of weeks. Which also means more factory images and goodies to be had.
Until all that happens, keep your eyes peeled. We will update you guys when we see the factory images showing up.
Via: Android Building
You can watch for the factory images HERE and the Binaries HERE