I disagree that the PS4 won't have a large graphical leap over the PS3. Simply put, every generation, people say that the leap won't be as big as the last but there ends up being a large difference.
The issue is that people look to AAA first party exclusives as the graphics norm for the current gen, it's the third party games you should look to in terms of how further they can go. I played the Mafia 2 demo on PS3 for example and it was terrible, not the gameplay but the visuals.. The game chugged and screen tearing was prominent. Also look at some of the open world games like Prototype, not a whole lot of detail in the game world, buildings look like models with flat textures pasted on top and many titles still aren't 1080p. Next gen will hopefully fix some of these things.
As for whether Sony have screwed themselves, I don't think so.
