If you like AWS or not: It's not a good idea to have everything in one account.
It's a single point of failiure anway and you want to distribute your core infrastructure between different parties. It's cool to run a DNS by AWS but not cool if you don't have mirrors/secondary nameservers, too.
It's a single point of failiure anway and you want to distribute your core infrastructure between different parties. It's cool to run a DNS by AWS but not cool if you don't have mirrors/secondary nameservers, too.