Sony was among one of the first manufacturers to be completely transparent about bringing Ice Cream Sandwich to its devices. Throughout the process, the company has posted numerous entries on its blog regarding the process, where they were at with various devices, and even offered up downloads of the beta product for advanced users and developers to test out.
With the most recent post, however, comes a bit of bad news: the Xperia Play has been dropped from Sony's ICS upgrade path. According to Sony, "after extensive in house testing with [their] developer teams and working with [their] partners, [they] have concluded that a consistent and stable experience, particularly with gaming, cannot be guaranteed for this smartphone on Ice Cream Sandwich."
The post goes on to say that this claim has been further verified by the development community, including "both experienced developers and advanced users, along with game content providers following [the] ICS beta ROM for unlocked Xperia PLAY smartphones."
It appears everyone was in agreeance: the Xperia Play just can't handle ICS and maintain a stable experience.