Keep the targets in mind, gentlemen...
The purpose and target of a powered suit would not be for conventional military application. We have more then enough of a variety of mechanized forces for nations to obliterate each other with that the only way to force the change was to up the defense procedures of biological components to the degree of manipulating quantum flucuations around them to alter the 'direction' of force-carring bosons.
However, modern war will not turn out to be the all-out national military industrial engine ferver it was in the early 20th century. In all reality, in Huntingtonian fashion, modern war will be a clash of civilizations. We will have our ideological/ethnic/religious/economical reasons for conflict that will heavily polarize certain regions of the world and will force kin cultures into making a decision about that conflict. This changes the battlefield of warfare entirely, from the traditional far away terrains to the macroscopic level of urban landscape.
The Cold War brought us a limited assurance that national-level industial complexes may never again compete head to head directly. Instead, they will fight via proxy. The Soviet Union did its share of proxy rearmament to most of Asia by producing 80 million AK-47 (and deriviatve) models during it's 50 year empire. The weapon was designed to simple to manufacture, intuiative to use, minimal part usage for repairs/cleaning, and durability so that poorly educated peasent classes could become of equal an force multiplication level of capitalist/industial armed forces. It worked wonderfully. However, these 80 million weapons remain in circulation in addition to RPG, mortar, and other light projectile explosives that could spell impending doom on a mechanized army in a heavily urbanized environment. (Review the Battle of Berlin for a disturbing example of civilian defensive mobilization and simple projectile explosives against heavily mechanized forces) These weapons are the hallmark of any political/religious terrorist because of their sheer abundance (yay Communism!) and simplicity. These are the weapons that we will be encountering on the battlefield because the flashpoints of civilization clashes will not be in the supraeconomic titans who have the most to lose in an all-out conflaguration of military powers, but of those who continue to ensure an unrestainable volume political instability for one reason or another. These political factions do not have the means to produce their own weapons, thus, tap into the nearly inexhaustable market of Cold War Soviet Arms with whatever funds they can raise. (Just as pro-Democratic forces in the 1950s tapped into the nearly inexhaustable market of Post-WW2 Western Weapons)
Thus, our prime enemy on the new battlefield of modern war will be the 7.62x39 mm round, the RPG-7's PG-7VL, PG-7VR, and TBG-7V rounds, and the British 81 mm mortar. The question is: Do we have the technology to defend against these weapons?
Yes. These weapons contain limitations that will not be upgradable by the third-world nations that rely on them. Once the technology is developed to stop them, third-world nations will not be able to redesign these weapons capabilities en masse and thus, any armor developed would provide long-term defensive capability to infantry units during civilizational conflicts. These civilization conflicts will attract the attention of kin cultures of nations who have higher economic influence which, in turn, the third-world nations will receive money, weapons, and training from these civilizations. However, technological adaptability against technological targets will be much slower since 1.) these industrial nations are not attacking each other 2.) these industrial nations are not within communication/hierarchial command of third-world military units 3.) any adaptibility against future technology will have to become increasingly complex (reducing the number of third-world units that can deploy such weapons) and expensive (reducing incentive to even give these weapons to third-world units) when compared to classical projectile weaponry. Thus, creating an armor that renders Cold War Communist weapons inefficient should be the top priority of Western military forces.
The carbon nanotube flexion/plamsa containment powe source combination appears to show the most promise.