The Project X Zone site has updated to include information on the revealed characters, voice clips, and screen shots. Here is a link to Valkyria Chronicles 3 section where you can hear Kurt and Riela's voice samples.
If you want to see the game released outside of Japan you need to show your support to Namco since it has been reported that they are the ones who get to decide whether or not to localize it. For the time being the best way to do that would be to post on their Twitter, Facebook, and message board.
Here are the links for those who are interested:
Localization Topic on Namco's Message Board