Well, if I had to guess, shadow detail might be a bit better, because apparently the Japanese version of NTSC would allow more of the inherent detail on the laserdisk masters in darker areas of Star Wars scenes to be transferred to the DVD's intended to be sold in Japan. Of course, that's assuming there even is a Japanese version, which I have heard no mention of at all so far. A long as they don't burn the Japanese subtitles into the movie (i.e., subtitles can be completely removed from the t.v. screen by an option in the DVD menu), then this could be a useful additional source for preservation purposes.
