People who joke about PS4 and that now it will take the place of PS3 on the limitations thing have no use what they say. Anyway 4.0 is still a bit too far away from now and we don't really now what will be improved due to to absence of PS3. Inventory increase could be a thing though one night argue this specific thing is more of a server limitation. They hinted about UI changes too which was limited by PS3 in many ways. It's not just about graphics. UI and gameplay also too a toll from PS3. Bow that it's gone they can start adding better and more complex features in game. PS4 is not holding the game back. PS4 in fact was underutilized due to PS3.