Google has pushed out a 14 MB system update over the earlier build of Android 4.4 KitKat (KRT16O). The change log for the build clarifies that the update only consists of bug fixes. Many are yet to receive the original KitKat update (KRT16O) due to a staggered release by Google.
It is to be seen whether Google continue to release the older build to those who have not yet received the KitKat update or straight away gets them on Android 4.4 (Build KRT16S).
In addition, Google has revised the factory images on their developer website to KRT16S from the earlier build.