When Google's Jean-Baptiste Queru revealed an "experiment" that would bring Sony's flagship Xperia S into the Android Open Source Project, Sony immediately announced its support for the initiative and pledged to help wherever possible. Today marks the first step in that process, as Sony has made the device's binaries — resources necessary to bring a stable, native Android experience to the Xperia S — available for download.
Sony continues to be a proponent of the AOSP idea, but the company seems to be taking a cautious approach when it comes to expectations. "Obviously a lot of more work is needed but we think it’s great to see the progress in this project," a post on Sony's developer blog reads, caveating, "even if we can’t be sure if this software will ever be stable and complete enough for daily use." Sony does say the provided binaries will allow the device to turn on and reach Android's home screen. From there it's all up to the development community, though these days that should give you more hope than any cause for concern.
Thanks, Floris W!