I think that if you are in a position where you are hosting your own infrastructure in a data center these wouldn't be difficult issues to address and are the b

I think that if you are in a position where you are hosting your own infrastructure in a data center these wouldn't be difficult issues to address and are the bare minimum in running that type of operation. You can front any website with a load balancer that proxies the connection to a IPv4 only back end and the major web server software such as Apache and Nginx supports v6 natively. If you aren't hosting the infrastructure yourself then you are limited in what you can support but you wouldn't be worried about peering, brokers, or up/downstream providers since thats what you would be paying the hosting provider for.