i don't know what to tell you, this ONFI 200MBps still sounds strange,
yet your ROC idea, afaik, just seems briliant.
why didn't any manufacturer did that,
are they all stupid ?
obviously such device/drive would be sold out on it's first week on the market,
i don't know if u've heard about it but, Intel's shipment of the 980 (~1100$+) chip has been sold out back a few weeks.
the market is there, even though it would be an MLC, such drive sounds simply INSANE!

to add a note here,
people who need a fast array can buy 3-4 disks as such, saving themselfs huge costs of buying quarter or at least half of the capacity of SLC's.
heads up lars,
beautiful idea/remark!