Killzone Mercenary is on the way for the PlayStation Vita, and will drop on September 17. But for the time being, Sony has given us a better look at what the game has in store in the above video, specifically showcasing a lot of violent melee touch-screen mechanics.
According to the developers, multiplayer is a "definite focus," and the game will ship with three multiplayer modes. At the current moment, only Team Deathmatch is confirmed.
Hopefully this won't end up like Resistance: Burning Skies! Sony doesn't have the greatest track record when it comes to portable spinoffs of their main franchises.
Killzone Mercenary [PS Blog]