Sarcos Raytheon's XOS exoskeleton was demo'd on Discovery Channel's Is it Possible? last night, and judging from the vast increases in stamina and strength, a real Iron Man doesn't look out of the question.
This exoskeleton, simply put, is a robot that you put on your body to completely mimic your actions and make you a "super you". It's run by a computer that receives input from six different sensors, and then relays that information to the suit to mimic the actions before the person in the suit even moves. And there isn't much movement that's sacrificed, either. Sure, it looks a little clunky when the guy is running, but he can still kick a soccer ball, walk up an incline, and lift weights with a certain ease. The weights, were especially impressive. The man in the suit did over 200 reps of 200 pounds and stopped not because he was tired, but because he was bored.
The suit is still a prototype, and it will only be used for military purposes, so you won't be able to buy this at a Costco next to vats of mayonnaise anytime soon. Which is a shame.