The tech driving Iron Man 3 isn't, as it typically is, Tony Stark's Iron Man suit. Instead, it's the medical-but-also-real-explodey Extremis. And believe it or not, the physiological nanoparticle science behind it isn't pure science fiction. At least some parts of it are within reach relatively soon.
Extremis works, to paraphrase the movie, by hacking the operating system of your body using nanotechnology. Dr. Shuming Nie is a professor in Biomedical Engineering at Emory University and the Georgia Institute of Technology, and says the concept isn't too far off base. He says that within 10 years or so, we can have practical medical applications of nanoparticles that not only enhance the human body, but make performing surgery easier.
One application (sponsored by the US Air Force) is already proven to be able to increase your optical detection sensory by "10 to the 14th fold", or 100 trillion (100,000,000,000) for anyone who doesn't speak nerd. That's enough to focus on a single molecule. Another, which could be ready as soon as a few years from now, is an injection of particles that would cause tumourous growths to glow, making them easy to find and remove.
Nie acknowledges that the more science fiction-y stuff will take 50-100 years, or longer, for us to get to. But still, that's not too long a wait for medical miracles/punching robots in the face.