Naughty Dog has issued an update to Uncharted 3 with a brand new experimental Lab playlist to play around in. The playlist is going back to a 5v5 format, this time giving players a combination of riot shields, uzis, and grenades to carry out to the battlefield. Kickback and boosters are disabled, too, so it sounds like your best strategy is to be vicious: Shoot everything until you get close enough to stab them in the back.
With this update, Naughty Dog also fixed an issue with DLC maps not showing up properly in the rotation, and there's a full rundown of what you'll see when on the company blog. The developer also promises a full schedule for upcoming labs and events soon, as well as more news about a new character coming to the game (from a Sony contest) and other updates in the next patch, 1.13.