Just it did for the Xperia S a while ago, Sony has now officially released AOSP version of Android 4.2 for its Xperia Z flagship.
Currently, the majority of the features on the Xperia Z are working in the pure Android environment. There's SD card support, Wi-Fi, Bluetooth, GPS and LED light as well as the sensors are all working well. The camera is also working flawlessly, but its code is tested internally at the moment as it requires proprietary binaries that the company can't publish right now.
Still, you can see how Xperia Z handles in the video demonstration below.
So, what's next? Sony promises that it'll replace some of the binaries with the original source code as well as release binaries for the NFC to work.
The project maintained by Sony senior software engineers Johan Redestig and Björn Andersson is available for you to grab on the company's official GitHub repository. Follow the source link for more information.