We probably should ban them at some point. However, personally I'd like to see an arm's race for the next couple of decades. Massive military spending could fund the R&D needed to get us to commercial uses. Jet fighters, and breaking the sound barrier were driven by the military, for example.

Having said that, I must say that I'm actually quite uncomfortable with machines deciding when to pull the trigger. Robocop is etched in my mind. Hope the remake keeps that scene.