I've compiled some documentation of Armed Assault II from the official website and if the game plays as good as it sounds, then look out Ghost Recon because this game is gonna give all of us Military Shooter fans what we've been asking for! Check it out:

SIMULATION:
In ArmA 2 a staggeringly vast array of military hardware is at your disposal. 73 modern weapons, 167 vehicle variants in the air, on land and at sea. The unique AI think and act independently, changing tactics on the fly. No scripts. No pre defined pathways. ArmA 2's AI share information, communicating with each other to hunt players down. They'll use cover and artillery, adapting to your actions and the changing environment.

WORLD:
Although ArmA 2 is set in the fictional ex-soviet state of 'Chernarus' the gameworld is actually a 225 square kilometer chunk of the real world! ArmA 2's highly detailed landscape is a meticulous facsimile of real terrain, modelled using extensive geographical data. This recreated region is brought to life with spectacular environmental effects and populated with dynamic civilian settlements and wildlife. Wild animals roam the atmospheric forests while the people of Chernarus try to live out their lives among the war-torn streets.