I wonder if Amazon is using an upgraded version of EBS / Ephemeral stores to provide higher IOPS for the RDS disk subsystem? Perhaps allocating higher throughput on the giant SAN so snapshots etc all work seamlessly. I'd like to see greater than the 72 IOPS they suggest EBS provides as an option. Amazon could allow selection of IOPS as an alternate parameter during EBS allocation. They could offer EBS stores that are 2x, 4x, 8x, Nx as fast - placing the volume on more spindles in the SAN environment and thus giving the higher IOPS needed for high write or very large data warehouse style databases. Alas, a boy can dream can't he?