As well as two new gameplay modes
Far Cry 3 keeps looking better every time I see it, and this introduction to it's multiplayer component is no different.
The folks over at Ubisoft have got the staples of most modern first-person shooters covered with a XP and level progression system and large area effecting, team support weapons. The most significant features to me are the addition of Battle Cries and it's new multiplayer modes, Firestorm and Transmission.
Being able to 'buff' your allies while under heavy enemy fire or while securing a node could help turn the tide of battle for either side, if timed well. I'm glad to see that fire has made a comeback in Far Cry 3, in it's Firestorm mode. Constantly changing the field of battle and throwing both sides into mad frenzy to get to the radio in time sounds like great fun.