Well I've just got back from the midnight launch at my local EB here in Australia.
I've put 4 hours into a friends copy of the 360 version game on the same TV that I'm now playing the PS3 version on.
Just some quick observations
-PS3 image is softer, but doesn't look "low res"
-Shadows and distant objects look less "dotty" than 360 version.
-Framerate seems slightly less consistant than 360 version particularly noticeable with the character animations during cutscenes and the intro.
-PS3 seems to have zero antialiasing. On the 360, the 2xAA was clearly visible on stairsteps (you could see the averaged pixels) on the PS3 I can't see any antialiasing being applied at all. However the softer IQ tends to hide the aliasing.
No pop-in of any note, umm noted
But then I never noticed any on the 360 version (Wasn't looking)
I would say overall I prefered the PS3 image. The 360 looks quite harsh in comparison and exibits alot of artifacting but on the other hand it's also sharper and more vibrant.
Just my 2 cents.