Awesome read about that link you posted. What really intrigued me was the comment about the launch era PS3s and the PS3s we have now....where in the old ones they would run in to bugs when streaming stuff and the newer ones no such problem...what all changed in the PS3? Surely not more RAM or higher clock speeds or bus speeds or faster hard drives?!
Like I mentioned before (and the article more or less too), it's all just because of the harddrives, nothing less. The PS3 launched with 20GB / 60GB harddiscs, and currently they are at 160Gb/250GB/320GB, and whatever anyone put in themselves (up to and including fast SSD drives). This has an impact. Once a certain speed threshold was not met, apparently this also caused a lot of virtual memory fragmentation - I don't know the details about that, but it is clear that they took the streaming from Uncharted 2 (which was still relatively straight-forward, and for textures only if I remember correctly from their GDC presentation), and took it a few steps further.