J-Stars Victory Vs. is a hot title for many anime fans, including those here in the west. According to J. Kartje, Community Manager at Namco Bandai America, "I don't know much about it - But I know it's complicated with all the licensing etc."
This is completely understandable. Bringing a host of different characters from different franchises can be extremely difficult. A big recently example was PlayStation All Stars Battle Royale, which failed to bring Spyro or Crash Bandicoot due to problems with Activision (who own the rights).
With characters like Monkey D. Luffy and Naruto, it may take forever for the parent companies to license them for North America. Either way, you can expect CGM to have a copy of J-Stars Victory Vs. when it hits Japanese shelves March 19th. It will be available for both PlayStation 3 and PlayStation Vita.