The cost of SSD's has been astronomical for the $ per GB rate, but of course as everything does this will come down as the technology matures. It's interesting in Tom's Hardware review that many mechanical HDD's have better performance per watt ratings than the SSD's do at this time, but as it's quite obvious by the OCZ results...this won't be the case for much longer.
Still, for 128GB of storage capacity at $479 it will be some time before I go looking at SSD's to replace my 500GB Wetern Digital Caviar 7200 RPM SATA II @ $93...shipped