As a kind of side point, I find it kind of interesting that Amazon is putting the EC2 brand front and center in this. You'd have to think it would be kind of surprising if they have really built it on exactly the same cloud that they are renting to 3rd parties - but that's certainly the way they are portraying it. It seems like they are almost trying to advertise EC2 to geeks as much as they are the Silk browser.