Right off the bat we should point out that this is different from its Concept for Android program, which basically reimagines what Android for Sony devices could look like. Even Sony themselves have made a note of this to help differentiate both of the programs from each other to prevent any confusion.
So what is the Xperia Beta Program? Basically it is a program that lets users sign up to beta test the upcoming Android 6.0 Marshmallow update. According to program’s description, “By signing up, you will be able to try a pre-release beta version of the Android 6.0 (Marshmallow). Most importantly, you will also have an open channel with Sony Mobile’s developers. Your feedback will enable us to release even better software for your Xperia device.”
The program can be signed up via the Xperia Beta Program app, so if you are interested in taking part in it (which has limited spaces available, by the way), head on over to the Google Play Store for the download.