If you want to see what the Japanese version of Final Fantasy XIII-2 will be like then watch the E3 trailer. Square Enix Japan re-released the video with Japanese voiceovers. Try to ignore the English text, though, the Japanese release probably won’t have that.
Here’s the English trailer, just in case you want to compare voice acting.
Final Fantasy XIII-2 will be released for PlayStation 3 and Xbox 360 in Japan this December with a North American release following in January.