At first glance it looks horrible, until you two shot an elite mob.
I've been flying through specs all throughout this game, and up until now they've all been acid rain based. Late in Act One the mobs started to kill me instantly because I had to sit there and channel spells to put out damage, I would literally die five to six times just trying to kill one pack of elite mobs.
So after much tweaking I came up with this spec. The idea is to put in a large amount of damage in a short amount of time and keep kiting around. As long as you don't get caught without spirit walk then you'll be fine on every pull.
Swapping out Jungle Fortitude for something else is a possibility, but you don't need anything relating to mana costs because this build doesn't run out of mana.
3938.72 Damage without buffs.
6613.73 Damage with five stacks of soul harvest
Average burst per setup:
50-65k for elite mobs
90-100k for trash mobs (they don't have that much health anyways >.>)