The Lost Patrol

Players are free to roam the entire world from the get-go, and up to 16 players can enter a single "open-world" lobby. From there, players can either go off on their own, or form an eight-player posse with strangers and friends alike. Even here, players aren't forced into one mode or another; players can join up together to attack another posse, ransack nearby towns or cause death and destruction to any of the plentiful NPCs scattered throughout the game world. Many of the non-story-related side missions are also available, like hunting down bandits or clearing towns of all their inhabitants, which should provide hours of entertainment outside of the actual multiplayer modes on offer.

If this is really coming to the PC, I am so in Pardner.