YES IMA WIZARD! 35 level, Act I of Nightmare.
Primary skill: Electrocute.
Decent damage, AoE capability and max range. With current perks, Electrocute seems to be the best primary skill for leveling. Magic Missiles often miss on moving targets and are much less potent for AoE, Shock Pulse has limited range/can miss (with Piercing Orb rune). Spectral Blade has very limited range while its damage is quite not enough to compensate that.
Rune: Chain Lightning, to improve its AoE further. Surge of Power will possibly be better to use, once it is available.
Secondary skill: Disintegrate.
1) Insane damage, insane AoE capability and max range.
2) LOOKS AWESOME. FEELS AWESOME.
Other three don't come any close, at least so far.
Rune: Convergence, to improve its AoE further. Chaos Nexus doesn't seem to be as effective. However, Intensity surely will be the best to use at higher levels.
Defensive: Frost Nova.
It is rather Defensive/Offensive skill, and it works great in both directions. Considering what a disappointment the teleport is, I can say that Frost Nova is by far the most useful skill for leveling.
Rune: Shatter, for the lack of better - Cold Snap is not working. Deep Freeze/Bone Chill will take its place later.
Force: Wave of Force.
Like Frost Nova, WoF has both offensive and defensive utility, and works great in both directions as well. It is often a life saver, and its damage is quite potent.
Rune: Impactful Wave, to improve its defensive utility. To be honest, it seems like I'm not going to replace this rune with any other.
Conjuration: No idea at this moment of time.
Storm Armor with Power of the Storm would be the weapon of choice for me, but sadly, it is bugged and isn't working at all. Currently, I'm using Familiar with Sparkflint rune, because it seems to be at least somewhat useful for offense.
Mastery: Archon.
There's nothing to be said about this skill, as it renders the other two completely obsolete right after you get it. Archon makes it up for any flaw the wizard has.
Passive:
1) Glass Cannon.
15% extra damage is 15% extra damage. This skill would be worth it even if the damage/resistance penalty was 50%.
2) Astral Presence.
This perk has the second highest offensive utility, at least if you're using Disintegrate.
3) Blur
20% melee damage taken decrease is wonderful. Nothing else seems to be as appealing so far.
I'd like to see other thoughts on the build from higher level characters. In general, I think there surely will be a cookie-cuter build with minor diversities:
1) AoE/Full offense
2) Single-target/Full offense
3) AoE/Defensive
4) Single-target/Defensive
5) Mixed/Full defense