So... I think you've got the spellsurges right there. That they act like runes from DK's in that they regen one at a time as they're used, and that's what the 2nd bar is for, to let you know how long the regen will be. I think Mana is simply for healing spells only. I believe I read that somewhere, but it could change. Usually mana for dps classes is indefinite anyway, and you might as well just get rid of them.