You might be wondering why this matters. Well, for starters, the first Android 4.2 devices (the Nexus 4 and the Nexus 10) won’t be arriving until November 13. Furthermore, Google has yet to open source the latest version of Jelly Bean.
This leak essentially means that hackers can get a head start on bringing Android 4.2, as well as individual features, to whatever devices they please. Developers who are itching to start working on ports no longer have to wait until Google officially updates the Android Open Source Project (AOSP). When that happens, it will still be important, but all the interested parties will already be one step ahead.
While the ROM in question is of course specifically made for the LG Nexus 4, and there are compatibility issues that will need to be overcome before anyone sees a fully working port of this dump, work has already begun. It won’t be long now before alphas and betas begin to surface for popular devices, like other Nexus products and Samsung Galaxies. I wouldn’t be surprised if stable builds arrived before the first Nexus devices.
If you prefer to try the components that came out before the system image dump, here are specific threads for the keyboard (Android 4.0+ required: general, Galaxy Note 2, Atrix 2) and camera (general).