Is this really a serious comparison? For one thing, those screen shots are way too small to do them justice. In the full shots the resolution is over 3 times more than PS3 can even handle; you'd need at least two gaming monitors to be able to display the res the demo is at. Then there's all effects that the PS3 hardware isn't capable of producing.
Don't get me wrong, the PS3 games are fantastic for the hardware and ND and Sony Santa Monica need to be applauded for their technical skills in getting their games to look as good as they do. However, there's only so much they can do versus modern hardware & techniques.
The resolution of the screens is a good point, when looked at on a high res screen, those shots will look fantastic.