So, i had the 360version and the PS3demo running side by side.  

The 360 one graphically surpassed the ps3 one. 

It wasnt extreme or anything.  The framerate on the ps3 suffered in a few spots which there was none of on the 360.   The textures and colouring appeared almost identical.(i found 1 instance of a better texture on the ps3 and 2 instances of better textures on the 360)(nothing of one having more vibrant colours) .  the main issue was the images on the 360 were sharper as the ps3 suffered from moderate jagged edges.  loading was the same, except for a couple instances of slow loading textures on the ps3.  the pistol on the ps3 looked fairly awful compared to the 360 one.  but the difference that stood out the most to me...the splicer standing over the baby carriage had a bunny mask on in the 360 version and had no mask in the ps3 version.

i will say that none of these issues would likely harm the experience of Bioshock.

I haven't played the 360 version, but I remember thinking while playing the PS3 demo "So that's where MrBubbles (from VGC) gets his name from." Now I know and knowing is half the battle.

I haven't played them, but from the looks of things they are not game breaking, and from what I have seen of Bioshock, it looks like a great game, so PS3 owners should not be put off by a few dodgy textures

They will be identical upon release........or will they?? Seriously though, these threads never end well, though I appreciate the opinion.