Screw Sony and their statements, things are seemingly not going where they planned it to be. Or is this a surprise, much like a trump card against Microsoft?
Due to some source code digging by Reddit, people have found out that not all PS4 games would initially be compatible, as updates from time to time would ease in the transition of old games being playable. Along with this, new-gen features such as haptic feedback JUST MIGHT be forced into the old games, giving a richer and better playing experience for the people looking into getting their hands on the new tech.
To add to the leaks, the source code also indicates on having multiple players use only one console, much like a Netflix family subscription. Also, it indicates that there would be cloud saving, wish lists, 100 person parties, and content sharing support.
In an interview back in September with Playstation CEO Jim Ryan, he exclusively stated how 99% of PS4 games would and should be working for the PS5, with the Playstation Plus Collection ushering in the entry of the old games into the new age.
The only thing to actually verify this would be the actual release of the console, so we all have to wait until November to actually figure this all out.