It’s a sad day for us all, as Sony and Google ended the experiment to make the Sony Xperia S an AOSP device. For some it was a beacon of hope. Could a regular device build up enough support to match a Nexus? Could more devices follow? It seemed entirely possible at the time, as Sony worked with Google to release as much code as they could. However, it was not enough, and it became clear that getting everything working may not be possible without proprietary binaries (which are not allowed in AOSP).
This is not Sony’s fault, nor is it Google’s. Sony does not have direct control over open sourcing proprietary binaries, the chip manufacturers do. They are the ones that prefer to keep everything closed source. There are exceptions, but in general, people have to work around them.
The whole project has been moved to GitHub. If you’d like to check it out, you can do so here. While this is a sad end to a good project, know that it isn’t quite over. Sony says it will open up some of the proprietary binaries. It’ll take some work, but their plan is to get Android 4.2 fully working on the Xperia S and continue from there. Sony, we wish you the best of luck. Your cause is noble.