I absolutely love the idea of a digital collection on a hard drive and all, but to be honest, if I really wanted something like that, I would use my laptop. That is not to say I will not be using it, though, as I bet not only I, but everyone can benefit from having, say, their favorite games directly on the hard drive so that the steps of getting up and inserting a disk are eliminated altogether. It could probably serve as a way to increase immersion, too.
Given that, I do not think I will be upgrading my hard drive above 1TB if such a thing is even needed, since the one that comes installed with the system can already hold more or less fifty to one hundred games. I doubt I even bought that many for the PS3 for the entire five years I have had it. I am certain some enthusiasts will be more than pleased to hear about this one, though!