What else are wizards running besides Frozen Orb?
I was doing a Blades/Meteor build before I happened to reroll +15% Arcane Orb damage on my boots (I was going for +Meteor damage). So I said eff it, switched to a glass cannon Frozen Orb build and things just started exploding.
I actually started with Arcane Orb - Scorch, bc I have a +fire damage Stone of Jordan. But that rune just doesn't feel right. The projectile itself does shit for damage, while the fire it leaves behind does most of the damage. If I'm lobbing giant balls of fire, I would think that them balls would be laying the hurt, not the crap they leave behind. Also, Scorch just doesn't have the width/aoe of Frozen Orb.
In general though, fire skills on a Wizard feels pretty lacking. It'd be nice if Blizzard changed a Disintegrate rune to fire. With my Meteor build, I was running with no runes for the fire damage to take advantage of my +fire SoJ. And running a skill without a rune is another one of those things that just doesn't 'feel right'