Ive had a play with the s3, i gotta say, it doesn't look or feel like any iPhone, it actually looks more like the HTC One X.
the screen is pretty nice & bright, seemed pretty clear, colour accuracy, not so much, it does the samsung thing of over saturating everything, making things look more cartoony, but to the effect of making pictures look very different to the iPhone 4s, which has very accurate colour (almost dull sometimes, wish the world was more colourful :P ).
basically at least looking on both screens the pictures turned out very different, i didn't put them both on a computer to compare.
id be interested in seeing what the comparisons say.
So did I about an hour ago and while it looks nice enough I still don't think much of Touchwiz. Much prefer Android with HTC Sense.
You would have to be a total idiot to think it looks like an iPhone.