These guns have already been sighted all over the map in PS2, hidden on the top floor of every Tech Plant. These prototype nanite anti air guns are being reported as being able to kill an aircraft with a single shot, however, they will render bases in trouble, because that single shot will drain massive amounts of power from the plant. Here is the rendering video, and considering the massive amount of work that has gone into these weapons, They will most likely come out in the near future, along with some changes to the tech plants to allow these amazing guns an extreme amount of viewing range to blast aircraft out of the sky.
And yet another fanfuckingtastic example of why I love PS2 and getting into it so much. You don't see DICE/EA being this transparent. Bye bye Battlefailed, hello SWEET sweet sexy lady! Planetside 2 is my pussy. Yes I have my shit bucket.