What is your fallback though if amazon loses your confidence? AWS infrastructures seem very nice, but aren't you hitching yourself to their wagon in a way that doesnt give you an easy or cheap exit strategy if things go south?

I keep hoping one day that they will open source the software that runs everything so that worst case scenario you arent SOL if you want to migrate away. Some might say that would lose customers for them, but it would probably gain people like me.