Well PS3 Games are rather large.
I'm now going to attempt to estimate the size of Portal 2.
As we all know portal 2 is going to be rather large so im going to guess it's about the same file size as Half life 2.
Now Half Life 2 is (according to my Pc) 5.1123 GB.
Now considering it's on the PS3 it'll be on Blu Ray therefore increasing the qaulity and increasing the file size by (im guessing) around twice the size so it should be roughly 10.2246 GB on PS3.
Blu-Ray does not work that way. If the game is bigger than
Half-Life 2, it's because either the game is longer or it has higher-res textures/higher-poly props or both. Now, obviously, it
will have higher-end graphics than
Half-Life 2 (all their recent games already do), but Blu-Ray has nothing to do with it.
Speaking of game size, I just did a check out of curiosity and discovered that the
Half-Life 2 Episodes both trump the entirety of
Half-Life 2 at 6GB and 8.5GB, respectively. What the heck?
EDIT: In fact,
Episode Two is bigger than
Left 4 Dead 2, and HALF-LIFE 2 ITSELF is bigger than
Left 4 Dead. What the double heck?