PS3 exclusives are huge.
Uncharted 3 - 47Gb
GT5 Spec II - 26Gb
Killzone 3 - 46Gb
MGS4 - 28Gb
All multiplatform games are gimped because of 360s small Dual Layer DVDs, they are no bigger than 8Gb for single disc games.
Those are not actually real sizes of the games though, remember the PS3 can't really use more than a DVD size of games anyway due to the limited memory, it simply doesn't have the memory t fit high res texturess, models, animations, AI, Maps+++ in the memory.
textures are what takes the largest toll here as they are the ones that are biggest, can be least compressed and give the biggest quality loss. a lot of PS3 exclusives have for some reason taken to storing non pre compressed textures on the disk to inflate the disk size. this of course have a few drawbacks. BD is already slow to load, you just slowed it another 10 times. in addition you will end up with LOWER quality, as the PS3 will need to compress the texture as it puts it into memory, instead of the artist pre-compressing it and being able to check the quality before choosing another compression quality and setting to avoid artifacts.
So I wouldn't look at the disk size of current games particularly, the only exceptions are car games(even there the PS3 inflated the size a lot for no return when you compare to Forza, which had more quality on merely two DVD's) which loads smaller "levels" at a time, and long RPG's that allows disk switching anyway, though the reason for the size of these are usually JRPG's with a lot of very big pre-rendered FMV's, which usually are so mediocre in quality the console could render it better itself for a fraction of the space cost and with much smoother sequence change between action and FMV.
So no, the 360 didn't really gimp anything, it often had bigger and better texture quality than the PS3 games, since it could actually use them.
Either way we're talking next gen, and we'll most definitely see a high capacity storage medium on both consoles for high res textures and model data for display on 1080 screens