Problems on all fronts:
1. Strength can't be achieved. Such thin armor against small shells, the world has not yet such an awesome alloy.
2. Flexibility not up to par, let's not talk about any of them personally. Let's look at the mobility of Boston's most powerful robot, which is a long way from Iron Man.
3. Power not up to snuff, the engines that can currently sustain this kind of flight performance for Iron Man are far heavier and bulkier. Furthermore, in order to keep those engines working for an hour, they would need to have Iron Man carry another bathroom-sized tank.
What's even more pessimistic is that even if all of the above were to come to fruition, Iron Man still wouldn't be born because humans simply wouldn't be able to tolerate the various advanced maneuvers that Iron Man does in the movies, such as Tony jumping from a plane to a stage in "Iron Man 2," which would have killed him outright if he had realistically been on the ground when he landed.
To say that the only thing that might be possible is the various electronics in the armor, but of course the level of sophistication would certainly be far less than that, especially with Ejavis, to the extent that it would mean that a super AI has been realized, and that it would be almost unthinkable for them to serve humans.
While Iron Man's armor is unattainable, a one-man support machine is still possible. Exoskeleton structures are a relatively small market for robots, but they could also be the most advanced part of a single device in the future. Initially used to allow disabled people to walk, such medical devices will inevitably end up being militarized.
The most notable recent investment is a $2.9 million investment by the U.S. Department of Defense (Darpa) and an attempt by a Harvard lab to develop a "soft exoskeletal structure," or what you might think of as a pair of athletic tights that can be worn close to the body.
Once this scientific research is generalized, it will change the rigidity and heaviness we've come to associate with exoskeleton dynamics. Soldiers will no longer need to worry about wearing three layers of clothing, and wearing three layers of clothing where a power outage will turn them into a living target.