OP here, this is my take on it. I agree with the CAG that said the PS3 case does look Next-Gen. The Wii even stepped up their game with white cases, but the 360 cases remind me of the original Xbox cases just a little brighter. And although the white labeling does stand-out from its predecessor, the size, cover art layout, is no different. So, I am going to say I prefer the PS3. I like the size and although the cases are smaller, they seem to be a little sturdier, IMO.
Now if the rumor holds true, about the new 360 console in development that is suppose to play blue-ray, I think they should totally change the look to resemble the PS3 games. It makes sense being that blue-ray is the new DVD format and Sony has followed suit with their games.