Nanoman is right in saying that the memory in the PS3 isn't really that much of a liability. I still get surprised every now and then at what the consoles achieve in their games with such apparently low memory compared to typical PC gaming (my system has 4x1024mb for example, which is 16 -!- times the amount of random access memory in the PS3).
Consoles have very low overheads. The OS is more streamlined and there are few background applications.