Let me type that again...

For two box levelling, I don't see how anything could be faster than two mages.

AoE, crowd control, AoE, unsurpassed single target nukage, AoE, free transport, AoE, free food / drink, AoE, no stupidly long class quests that can't be avoided, AoE, three *viable* damage types (fire, frost, arcane) so less worries about immunities, AoE...

Oh, and mage AoE is pretty nice too.