Damian Thong (Damian Thong), a well-known analyst, who predicted the advent of the PlayStation 4 and PlayStation 4 Slim, believes that the next console from Sony will be available in 2018-th year. That is, the PlayStation 5 will be released 5 years after the launch of the PlayStation 4.
Official reviews the Sony does not, but, if Tong is right, then most likely the announcement of the PlayStation 5 will happen either in late 2017 or early 2018. There’s also the possibility to see the console at E3 2018.
To motivate the acceleration of the current generation Sony could release a very powerful Xbox Scorpio.