I'm sure I'm not the only here who despite welcoming this news as it's the next stage of evolution for the ArmA series; will also have a sense of déjà-vu. Simply because by the time the game will have come out, once more it will not have been properly optimised/be too taxing for current systems. As I understand it, "ArmA 2" and "OA" do not utilise more than 3GB of RAM? In addition they do not use more than one core of a processor? If so, this should be addressed by B.I as it would be sheer madness not to take advantage of such technology given the scope of the ArmA series.
I realise that to render an island and all of its rich detail requires a lot of work by a processor and realistically, we're talking about processors in excess of 4GHz here to get very smooth frame rates. Which will only be achieved by consumers overclocking their processors. An unecessary requirement. So please, do optimise the game to be more hardware friendly whilst not compromising on the quality and standard that the ArmA series is known for.