Gamigo announced today that Martial Empires will not be accessible outside of Europe after launch due to legal issues -- agreements with the developer prevent it, but no other details are given.
The changes will take place at the game's official launch, so if you live outside of Europe and are participating in beta testing, you can continue to do so, for what it's worth. Check out the Martial Empires site for the full announcement.
[Update: One of our commenters has found the Martial Empires NA version, and it's going under the name of Seven Souls Online. Thanks for the pointer, BubleFett!]