Amazon doesn't run their site off the same set of EC2 servers and systems that everyone else does. They just used their experience to build it.
That would be the ultimate testament, maybe the only stunt they could pull to PR themselves out of this mess.. if www.amazon.com ran on the same set of EC2 servers and systems as us muggles
Amazon runs all of the Amazon.com web servers on EC2 hosts (and has since 2010: https://www.youtube.com/watch?feature=player_detailpage&...). They've just made sure that they have enough hosts in each of the other AZs to withstand an outage.