Two Storage Hierarchies?

There was an interesting blog today from Steve Duplessie, on the potential end of the disk era. Of course its incendiary stuffand of course the timescales Steve offers may be off a little (one way or the other.who knows whats around the corner?)..but the ultimate logic is surely correct. After all, nowhere is it written that storage shall spin!  Indeed, all weve done for decades is attempt to deal with the challenges that the rotation produces. Now, of course, it isnt that disk has been all badtheres a famous Winston Churchill saying that goes something like: Democracy is the worst form of government ever invented..except for all the others. Disk falls into the same categorywe havent been able to afford to do effective storage any other way. But once that economic barrier is lifted, then we will make this shift.  And thats when I propose that we stop thinking of a single storage hierarchy.

Instead, imagine two: each could itself be composed of multiple tiers and the actual media could include things weve barely yet imagined, yet alone manufactured. One would be a Production IO hierarchy and the other a Retention hierarchy. Or active IO and long term retention. Its the difference between the clothes in your closet and your basement storageall valuable stuff with a purpose, but you dont try to manage it all the same in one room, do you?