Square Enix have confirmed this evening that their upcoming release of Lightning Returns: Final Fantasy XIII will feature the original Japanese dub as DLC content in addition to the English dub included in the release. But fret not about paying through the roof for it if you are an early adopter, as the Japanese voice-overs will be free to download for the first two weeks until they revert to paid DLC.
The Japanese Voice-Over Pack also includes lip-synching that differs from the English-language voice track already included with the game, to ensure a more natural and localized game experience.