We know from June that we'll be able to play PlayStation 4 titles on PlayStation 5. Undoubtedly, this was great news for fans of Sony consoles, because the current-gen does not offer the option to play games designed for the previous device (and remember that in the case of the competitive Xbox One this is already very much possible).
It turns out that there is a great chance that on PS5 we will be able to play not only titles from PS4, but also those much older. A Twitter user called PSErebus, who is responsible for e.g. the leak of the release date of The Last of Us 2, has informed his followers that they should not sell their games from PSX, PS2, PS3 and PS4. This may suggest (although not necessarily) backward compatibility of PS5 with older versions of Sony consoles.
Of course, for the time being we should refrain from shouting joy all over the web, because the information has not yet been officially confirmed. It should be expected that if it is at all true, then we will have to wait a little longer for Sony's official position on this matter. The fact that PlayStation 5 would support titles from older versions of the console would certainly contribute to a significant increase in the popularity of Sony.
There is also a photo of PS5 devkit on the web, which confirms the appearance of the developer version of the device from the official news. Of course, this does not mean that this is how the console will look like, which will hit the store shelves next year. In the photo you can clearly see the front part, all buttons and USB ports.
PlayStation 5 will be available on sale in 2020 in the run-up to Holidays. The console will offer support for ray-tracing, will allow for faster data loading, and will have improved controllers. The device will also support 4K resolution with 120Hz refresh rate.