With every almost big country having Missiles and if not, at least RPGs and shoulder deployable ones like stinger missiles, and ever major country developing/deploying an anti-missile shield (with Israel and US leading them), the next generation of weapons needs to be developed. My guess or rather a way to it is developing missiles which can detect incoming anti-missile and rapid change trajectory/direction randomly more than once to shake off the incoming anti-missile. The one who does this can avoid the missile shield successfully. Though it may not be possible to hit the targets which are protected by the anti-aircraft/anit-missile guns (these have a very high rate of fire, and create something more like a wall which blocks the incoming missile; the closer the missile gets to the target and maintains its trajectory, the easier it is for the gun to stay stable and fire at the missile).
