Draw distance comparison. Make your own conclusions.
The helicopter in the PS3 shot is closer to that area circled also. But that area isn't the only place where objects aren't being drawn. The city skyline is also missing a ton of detail in the PS3 version. Is it the weather? Maybe. Maybe not. I know, maybe the PS3 is also Folding@Home in the background while playing GTA4.
This video also shows the Vaseline filter (as it's now being called) on the PS3 version.
Grand Theft Auto IV: Graphics Comparison - Game Trailers, Game Reviews, Gameplay Videos at VideoGamer.com
LOL. Wonder wanted this added too:
^^^ That shit is funny/