It's the tale of all PlayStation 3 games, the dreaded mandatory installation process. Lately, the mandatory installation has toned down, but every so often we get a major release and we find out it'll require a designated space of our HDD in order to play. Every Capcom title released, thus far, has required 5GB of space for the installation. It looks like we'll have to cope with mandatory installation again with Uncharted 2.
Naughty Dog has just officially stated that there will be no mandatory installation for Uncharted 2.