US Army is working on developing an "Iron Man" suit (see this WSJ video). Be warned though, flight capabilities and repulsors are still a long ways off. It is hard not to be skeptical about this actually being implemented. Though, I have zero problem with the research. I supect by the time we can develop a battle-worthy exo-suit, we will also be more likely to use ground based drones instead, i.e., Sentinels. Let's just hope they are not programmed to hunt down mutants.
