I'm surprised people think the graphics are taking a big hit due to 360. My view, as a PS3 owner, is that graphically the consoles are very close. I really wouldn't expect being multiplatform to affect that.
There is only one area there is a factual difference that could have an impact - DVD storage vs BR storage. The only affect I can see (apart from getting extra exercise if you own a 360) is the game world layout might be designed to better align to being split in two - as with Rage where they altered the landscape from an initial design for three large gameplay areas to two to better align to shipping the game on 2 DVDs for 360.
I suppose you could get all angry and claim this is somehow 'downgrading' the design, but I fail to see it having much impact myself. And if you're playing on PS3 you will have everything on one disk and will have seamless play anyway.
I think in the end too many people are looking to see more issues here than there likely are.
Try to be reasonable... its easier than you think...
