At some undetermined point in the future Flynn said Fusion-IO will start using 2Ynm flash, 24-20nm NAND, which will make denser and cheaper flash storage possible. He's anticipating a doubling of the ioScale card's capacity up to 6.4TB. Have four such cards, two per server, in 1.5U of rack space and you'll have a 24TB flash store.
He anticipates a 6.4TB ioScale card using the 2Ynm process flash would have half the per terabyte cost of the just announced ioScale, which happens to be $3.89/GB - with volume sales getting discounted pricing. And then there's TLC flash waiting in the wings from 2014 onwards. It's just going to get better - or much, much worse if you're a performance disk manufacturer.