It seems a person buy a Nexus 4 an employee of Google and arriving at his house discovered that he had 4.3 Android (Jelly Bean) instead of Android 4.2.2 (Jelly Bean) and with the compilation JWR66N, the same as filtering Android Samsung Galaxy S4 Google Play Edition 4.3.
For now it seems that it has the same improvements that we saw a few weeks on the filtered version of the version of Google’s Galaxy S4, i.e. few improvements regarding Android 4.2, although it could be an early version of Android 4.3 and finally have more news or simply still all undiscovered.
4.3 Android (Jelly Bean) It could be presented on July 24 and its update to Nexus devices would come soon. The announcement of the new Nexus 7 is expected in that same event. You can then download the system files of the filtered version of the Nexus 4 4.3 Android (Jelly Bean). There is still not a ROM available to install.