Seeing as the 20GB PS3 is all but killed off, Sony's plan of confusing customers with multiple price points (see Microsoft's 360) is quickly coming to an end. That's probably why Sony's just announced that they're considering re-launching the PS3 with bigger hard disks. This confirms what Bloomberg said yesterday about Sony's big disk dreams.
Other than swapping out storage, Sony says they don't plan on swapping out any of the important components such as the Cell processor, RSX, or the Blu-ray drive. Stuff that developers count on to make games that run correctly on all PS3s, instead of the PC-model where everything's built piecemeal.