I posted a much less developed version of this a while back, but having played around more in the beta since then, I wanted to approach it afresh.
Plenty of people have noted the potential of both Gruesome Feast and Grave Injustice. Having thought it through, I think combining the two is going to be a lot of fun. First off, here's the build:
A couple of design goals:
1) Don't waste skills. We only get 6 actives and 3 passives, so every skill should be doing something for you as often as possible.
2) Conform the character's abilities to how you expect to be fighting. Given what we've heard, and what I've experienced in the beta, D3 will involve a lot more smashing through mobs and less frequent 1 on 1 boss battles. So we keep this play style in mind when picking skills.
3) The game will get harder. The beta is a breeze, we all acknowledge it. But I don't see any reason why we should assume that we won't need to be careful in later acts and difficulties.
On to the explanation. The primary approach with this build is to work is to keep killing at an even, but brisk pace, continuously stacking damage bonuses from orbs while simultaneously speeding up cooldowns with kills. Making orb hunting a priority allows for more mana intensive kill spells, since each pickup nets you 10% of your mana (note: a % that scales with manapool size, meaning that +mana is better than +regen rate for this build). 50% Int boost (with 5 orbs) is no joke (again, % bases, so it will scale unlike Soul Harvest).
Primary Killer -
Firebats: Hungry Bats. All the runes cost the same, so we might as well get the most damage out of them. At 280% Weapon Damage, this is quite respectable. From skill videos, it appears that this variant sprays mini direbats continuously at whatever is nearest. This means getting close, but save you the effort of tracking foes. Mana intensive, but we'll constantly be gobbling orbs, which should offset this.
Secondary CC -
Grasp of the Dead - Death Is Life: GotD is a fantastically useful CC spell on its own (as beta experience shows) doing DoT and slowing down mobs. The fact that we can rune it to give us more shots at globes is gravy. Plus, it combines well with...
Spirit Barrage - Phatasm: This probably raises some eyebrows. Like more people my initial impulse is to look at Spirit Barrage and think "Spirit Is Willing is auto-include for spamming against bosses). Maybe in an ideal world, but remember that much much more of the time we will be fighting large groups of monsters at a time, rather than the Skeleton King or the like. This turns barage into a neat little DoT circle that you can macro together with GotD to give you a 65% damage, 60% Slow kill zone that yields globes. A cooldown of 8 seconds will vanish almost instantly once you kill a few monsters (remember, every kill chops off a second thanks to Grave Injustice) Plus, it LOOKS from the language like you can actually spam and stack these, though its not 100% clear if the same DoT spell can stack on itself (maybe not - though in the case of Blizzard, they go out of their way in the tooltip to actually say this, which implies that if they don't say it for another skill, then it can stack).
Damage Buff -
Soul Harvest - [Variable]: This one really IS auto-include. Even though it will have a proportionally smaller impact when you are in high level gear getting big Int bonuses, it is still a pretty hefty boost at lvl 60 (and bear in mind that 650 Int also = 65% resist all). I think that I will wait and see what problems the build has before deciding on the rune. If life is an issue, healing. If mana is a problem even after orbs, then the mana rune. If nothing is a problem, then maybe just damage or slowing (to help get out of the middle of enemies after a cast). The main point is the buff here, so I'm flexible.
Support/Cooldown Abuse -
Fetish Army: Devoted Following: I will admit, none of us have any REAL idea how most of these high level big cooldown skills like Fetish Army, Mass Confusion or Big Bad Voodoo will really work out in practice. I want to take advantage of big cooldown reductions, so this slot needs to go to whatever is must helpful. Army seemed like the best idea to me since it would help with elite pack encounters both offensively and defensively as a distraction. Maybe I'm wrong, but whatever ends up being the best long cooldown spell should go here.
Gargantuan: The Witch Doctor isn't a tank, but this build requires getting up close to kill a lot. While orbs will help, I think having some reliable meat shields will also help. But remember our goal is killing mobs and elite packs. AND remember that we like to abuse cooldowns. Well, Restless Giant looks great for handling elite packs... only 120 seconds is a long time to wait. What if you run into another pack before then? This is where an assumption comes in. I am assuming that if you recast the Gargantuan, it will reset the "only every 120 seconds timer". Meaning that every 60 seconds minus the number of enemies you've killed in range, you get to refresh CLOBBERIN' TIME (or Hulk Smash, depending on your preferred comics reference). If I am wrong about the timer resetting with a recast, then Wrathful Protector is the obvious choice, as you can keep him out fairly consistently(45 seconds after he expires minus number of enemies kills from when you cast him).
Gruesome Feast: This is part one of the entire engine of the build. Damage buff, healing AND mana regen all in one. Just fantastic. Also, having played the beta quite a bit, health orbs are decently common. Not all over the place, but you seem them regularly. Plus, you see more of them from boss packs. And finally, I looked at the datamined affixes and yes, there is an affix that gives you +10% chance to find orbs. Every little bit counts. Now fingers crossed for some awesome Legendary or Set item that has some silly large health orb bonus...
Grave Injustice: Part two of the killer combo. The fact that this ALSO gives you a little life and mana for each kill is just wonderful, heart-clogging gravy. Now, many of you will be thinking "okay smart guy, but you have to be REALLY close to have kills trigger this." Right you are! Unless of course you consider that almost every armor type can spawn the Increase Gold-Find Radius affix and that that affix tops out at 9 meters. Then you begin to see that with the right gear, your area of influence may as well be the entire screen. Which brings us, finally, to...
Circle of Life: I'm sure there will be disagreement about this. Lots of things could go here, Jungle Fortitude for survivability, Pierce the Veil for raw damage etc. But I'm into synergy like a corporate management consultant on coke, so I picked this one. Why? Well, meat shields are always nice. Even nicer when they are FREE and you don't have to think about summoning them. But best of all, the same gear that boosts your radius for Grave Injustice, boosts your doggy spawning radius (plus it gets us 3 dogs without having to use a precious, precious active skill slot. In beta play I have found that you get up to three quite quickly, so with the pace we're after here, having them out all the time should be easy. Oh, and of course all those orbs you'll be gobbling heal them and your gargantuan as well.
So, what do you think? I'd love any and all constructive comments/thought/criticism. I am personally really really excited to try this out as my starting build and I hope its given some of you ideas too.