I would guess that it depends on what you call power armor. Are you talking Fallout type Power Armor, which we aren't to far away from, needing only an effective power supply (magic maybe?) and lots of money. Not cost effective with current tech, but a few years and Magic could make it so; or something closer to the Mjolnir Power Armor (Master Chief's) from Halo?

I just read this, grammar fail. Oh well.