Again a storm in a glass of water? They seem virtually identical to me despite the extra development time:
http://www.videogamer.com/videos/player.html?vid=2219
As expected, some improvements Sony made to the engine are universal (better cache hits for example), so this benefits other platforms as well. But the Unreal engine is more a 360 focused game engine like I said in the past, Epic made statements which seems to indicate it's unlikely they will bother to get the most out of the PS3 architecture through PS3 orientated game engine enhancements. So their games and likely games based on their engine will probably remain roughly on par, as expected.