What is a Diablo 3 Warlock? It is a Wizard that uses a 2 handed weapon rather than wand and orb. Preferably this would be a staff, but other 2 handed weapons would suffice in a pinch. The core idea is to maximize AP efficiency, thereby allowing you to spam high arcane cost spells. I see the Wizard attacking with a high pitch screech, while the Warlock attacks with a low roar. Here is one of my HC build ideas that I have centered around this concept:
Arcane Orb would work fine as a replacement for Disintegrate, but I am also trying to follow class lore from other RPGs which usually involve the ability to use fire based spells.
Note that the Volatility rune on Disintegrate, Calamity rune on Teleport, and Wave of Force only get one tick of your weapon damage rather than using your DPS. So those will all do more damage with this build vs. a wand and orb build.
If you need even faster AP regeneration, you could use storm armor with the power of the storm rune. Another possibility would to be to use Diamond Skin with the PRISM rune to lower your AP costs by 7. The cool down time on Diamond Skin is already pretty fast, but you could always shave a couple seconds off of it by using Critical Mass.
The choice of spells is mainly designed with the idea of playing keep away from the bad guys rather than minimizing their damage, so when selecting gear for these builds, go for high intelligence and damage output, rather than a high armor rating. Also, items that increase your main damage will be more important than items that increase damage by increasing your attack speed, since your damage will probably be limited by your AP regeneration rate.
While working your way up to this build (and waiting to unlock some of the runes), you will probably need more AP, so here is a build that you can use starting at level 30 that includes a signature spell for that extra AP:
Time Warp rune and Glass Cannon damage bonus should be multiplicative in this case, resulting in 38% more damage.
I would love to hear your comments and opinions!