I might be rusty...
But is this not hierarchical storage by another name? Of course back in the day it was optical jukeboxes that seemed to be the flavor of the month for long term storage. To be honest this object storage stuff is new to me but it seems like it might be out of a job if memristor based memory delivers on it's promises. Or perhaps it's complimentary since it seems to be more of storage technique than a new medium.
At any rate I've never been exactly confident about long term tape storage. Seems converting archives to new tape technologies is a time consuming and expensive endeavor as well. /Shrug. Guess it all depends on the volume of data and if you need to ensure data integrity (as in read only WORM media).