Master Gecko has shared many important points about WD.

Just something to share and ponder.
Among all heroes, based on my experience, building WD is quite different.

Of course you can build your WD like normal route, stack up IAS% to push up your DPS.
But more IAS, sooner the mana drained. Therefore, it is not necessary for WD.
WD don't really need IAS to push up your "paper DPS" because WD has 2 deadly skills with awesome burst damage, bears and bats, to kill fast.
What you need to concern is, do not let your mana drop low so that you can perma-spam your bears and bats.

So, without high IAS, one thing you'll find is low DPS (just like ZD-Sacrifice build). It is just low "paper DPS"
Do not let the low paper DPS fool you, WD can kill extremely fast with bears and bats (thanks to the burst damage).

To give you some ideas on how deadly WD is.
Here are my heroes,
HOTA/WW/Rend Barb 310K DPS
Bell Monk 295K DPS (will be 300K+ DPS once I reach paragon 100. It will take forever though  )
Bola/Spike trap DH 420K DPS
CM Wiz 275K DPS (will be 300K+ DPS soon if I am no slowpoke in bidding gloves  )
B&B WD 221K DPS

My WD has the lowest paper DPS (since IAS is not aggressively stacked).
Based on my current build of all my heroes, WD is the top killer for me.
If it's 1-1, HOTA barb could do better. However, when it comes to multiple targets, bears and bats of WD just melt every @ MP10 easily (especially solo game).
Every bear can deliver 950K-1.3 million damage per hit (a bear can hit multiple targets. There are infinite bears when you can perma spam bears).
Bats give me 2-3 million damage per hit per target (when you can spam bears, spamming bat is not a problem due to lower consumption of mana).

P/S Skorn with LS is the best. Really awesome weapon. Put ALL your gold and invest on a good skorn with LS. No regrets, whatsoever.

Good luck in building WD.

1) 4 set Zuni is a must. You need that 20 mana generation.
Yes, you have to stack a lot of IAS if you want to go on top of DPS chart.
But it will drain your mana fast, which is not really good for WD @ high MP, IMO.
Mana is very important for WD in dishing out burst damage skill. I think only ZD-sacrifice build doesn't need mana.
This is why I said WD has a quite a different build.

2) Pros and cons between 1H & 2H.
The major benefits of skorn are, beside cheaper price (as compared to 1H+mojo), (1) high base damage (2) 6% LS (3) Mana management.
I started off playing 1H + mojo. I tried to gear mana generation on voodoo mask+mojo+ceremonial knife.
And after using skorn, I found 1H build just doesn't have efficient mana management like 2H skorn.
Mana is very important for burst damage skills, generally.

3) Wiz has extremely fast arcane recovery through APOC gears + attack speed +passive.
WD does't have such fast mana recovery.
Therefore, to make sure mana doesn't drain or drain fast, slow weapon is used / IAS gears not required.
As mentioned in point (2), 1H drains mana, that's the only concern.

4) For WD, it is the choice of skill > DPS.
INT, you keep in the range of 2500-3000, that's normal. The more the merrier.
CC, keep more than 40%
AR/VIT/Armor are important. It's all bout EHP. Keep your EHP at around 500K (based on 3dup, with jungle fortitude passive). If possible, keep 600K to have a comfort play.

5) Yes, it's EHP after all.
For my CM Wiz, attack speed is very important. Need to get 3.0 attack speed or more as it affects LOH and APOC recovery. And these eventually affect the survivability.
Because the very first concern for me is to get 8-9% IAS from 9 gears (in order to get 3.0 attack speed). Secondly, I need to get CC.
I'm not sure about others, for me it's not easy to keep 5K armor if I want to achieve +80% IAS and +54% CC.
Not so easy and cheap to get those "perfect" gears.