Drones. Obviously a highly controversial issue with the old society under surveillance stuff - very scary.
I think the reaction to them as a weapon system is rather futile - Much like the reaction to the longbow in the middle ages. Really, we should press home any strategic advantage in the theatre of war. Our overall strategy of "killing for peace" may actually be the problem which is fueling insurgencies.
In terms of weapon systems I think they will develop a lot more over the years. Basically we are still using them as glorified aircraft. Here is a group system which has a much larger surveillance and targeting ability. Effectively intelligent mines which work together and hunt people down... I kinda wish I could un-think of this.