There may not be a North American release date yet for the Vita-ized version of Earth Defense Force 3, but it's due out in Japan at the end of next month, and details are starting to emerge.
The game is apparently a port (of sorts) of 2007's Earth Defense Force 2017. It's got slightly better graphics, but ultimately it still seems to be all about using overpowered weapons (over 150 of them!) to kill hordes of oversized bugs and destroy every building in sight.
There are a few new wrinkles, though. First and foremost, players now have access to jetpacks. Secondly -- but perhaps more relevantly to the Vita's fate, when you consider how much of a system-seller Monster Hunter and its co-op mode was for the PSP -- EDF 3 will have both local and online four-player co-op.
Again, there's no North American release date at the moment. However, considering the dialogue will generally be variations of "Giant bugs! Kill them all!", it seems like the game will be a fairly safe bet to import, localization or no.