Recently there's been a rumor that Sony is planning on releasing stock AOSP ROMs (clean, Nexus-style builds of Android) for some of its high-end phones and tablets. It's easy to understand why Sony in particular might attract that kind of attention: the company has better support for aftermarket development than most, promptly releasing binaries and source code on the company's own GitHub and even some developer-grade AOSP builds. But as for consumer-ready, finished and fully supported AOSP ROMs? Yeah, that's not happening.
At least not yet. While this blog post says that some of the members of Sony's development team love the community that's grown up around its open source Android releases, there are no current plans to support retail Sony Xperia hardware with full AOSP ROMs. (With the exception of the Z Ultra, I suppose, notably missing the "Xperia" branding.) But Sony's Developer Relations specialist Alin Jerpelea, himself a former member of the FreeXperia project and CyanogenMod, says that it's an interesting idea.
Please note that the binaries and source code provided by us is not enough in order to build a fully functional custom ROM. Instead it’s our ambition to provide a stable base, to make the work for community developers as easy as possible. We’ve seen some speculation about Sony planning to release AOSP ROMs. It’s not currently our plan to share such AOSP ROMs, but certainly, some of the feedback we’ve seen to this idea online is interesting!
The AOSP builds that Sony has released for a handful of devices are little more than experimental builds - they don't include Google apps, and a lot of them have problems that make daily usability a stretch at best. Sony's practice of releasing its hardware with easily unlockable bootloaders, with only a few exceptions, has been met with appreciation. And above and beyond support for developers has earned it respect in the ROM and modding community, not to mention disproportionately high support from CyanogenMod. As OPPO OnePlus has proven, there's a market for enthusiasts who want "pure" Android and easily moddable phones. Let's hope Sony is up to the challenge.