Just yesterday we saw Google rollout Android 4.2.1 first to Nexus 10 devices, then to Nexus 4 devices, and then to Nexus 7 devices. While the update was hardly an improvement on Android 4.2, it did bring that December fix the the table. Some devices are still receiving the update to Android 4.2.1, as this is an OTA update, which usually isn’t available for everyone at once. While everyone waits for the update, users might be happy to hear that the source code is now in the Android Open Source Project (AOSP) according to Technical Lead Jean-Baptiste M. Queru. According Queru, we should be seeing some factory images for devices within the next couple of days, which is great to hear!
source: Talk Android