Is Battlefield 3 not hardcore enough for you? ArmA III has tanks that leave a heat trail when they shoot a round! At least, they do in this trailer that seems to mix live action with some trademark ArmA graphics.
The new ArmA will have a full and open-ended singleplayer campaign, PhysX support for vehicles, interactions and animations, cooperative and competitive multiplayer with dedicated servers for both Windows and Linux, and an integrated mission editor.
Jordan posted some screenshots earlier if you want to fap over how great it looks, or weep over your current PC specs.