Anime fans generally fall into two camps: those who hate dubs and those who prefer them (there's also a third camp: those who don't give a damn). The same is basically true for gamers. Some just prefer their localized games to have the original voice acting intact.
For Phantom Brave: We Meet Again, NIS America is catering to the whims of both groups by putting in dual English and Japanese voiceovers. Here's a blurb from the NIS America press release:
In appreciation of all the great fan support, NIS America negotiated with the developer in Japan and they have happily accepted the request. The development team has noted that as long as fans and gamers can enjoy Phantom Brave we ll do our best to get this feature in .
The implementation of this feature is a double-edged sword, however. Due to the extra development time needed, Phantom Brave: We Meet Again won't be meeting its June release date. It will instead launch on August 4.