What would really be groundbreaking is to allow non-US based viewers to subscribe to the service, without any type of geo fence. I would be happy to pay for the service as a European consumer. That would mean no more GoT torrenting for me.
I am assuming that if they did open it up globally, they would not be able to sell the shows for as much money to other networks.
That said, subtitling from English is fairly cheap, especially at the current level of quality, so there's no reason to avoid it.
This service will be offered in the United States and there are also plans to bring it overseas