Kingdom Hearts: Birth by Sleep is done in Japan, but Square Enix may polish the game before it comes out in the West.
In a Famitsu interview transcript, Tetsuya Nomura discussed possible changes for the Western version of Kingdom Hearts: Birth by Sleep. Some bosses Nomura felt were weak could be stronger in the English release. Megaflare is too powerful and he plans to adjust the spell. Nomura also mentioned putting a “critical mode” in Kingdom Hearts: Birth by Sleep.
Square Enix USA has not announced Kingdom Hearts: Birth by Sleep for North America. We haven’t seen anything official from Square Enix Europe either. However, if Nomura is talking about an international version, it’s safe to say it’s coming over eventually.