Apart from the other answers pointing out this is fairly possible with modern/future technology, I would like to point out another reason this is impractical and will probably not be developed further:
Iron man seems to hold his own when boosted from the bottom, balancing himself with boosters on his hands. But in reality balancing on boosters from your feet is extremely tricky. Imagine balancing yourself on two long flexible poles stood upright. Only with extreme balance and strength you will be able to, but one slight muscle twitch and you'll find yourself doing the splits. And when the boosters are no longer pushing from underneath you, they will push in whatever other direction, sending you flailing randomly and going very much splat. Imagine blowing up a balloon and letting it go without tying it. It will boost randomly anywhere because it isn't balanced. Especially the higher up you fall from (meaning you need to reduce more speed) the longer the boost, and the rate of failure will increase significantly.
Of course, this will be different with jet packs, as they are more strapped to the centre of mass (back/sides). However this will still be tricky as you use your legs as stabilisers. The size of these compared to the body will be fairly big, meaning you will be able to carry significantly less gear. Even if an exoskeleton is used, the weight of the exoskeleton will add to the force needed to slow down, so the size will have to increase significantly to account for this.