The Exchange Product Group is maniacal about storage - probably because it is one of the single biggest cost for the platform. Keep in mind, however, that they are not experts in storage technologies, have NEVER produced a commerically-viable storage platform (who is running Windows Storage Server?), and their solutions are not tested against real-world operating environments. It's facinating that they did a JBOD implementation with slow laptop-quality SATA drives for some poor unsuspecting customer. But what you won't read about are scalability, expandability, and operational complexity that the solutions involve. This current crop of "pundits" needs to fade back into the woodwork.