Casters SHOULD do more dps than melees

[Arctigis]

See, you're right here. They SHOULD do more DPS, because they SHOULD be about resource management.

But there's a problem. Take the Arcane Mage prestige enhancement for Wizards. Arcane Bolt does 1d6 damage/level up to 20d6, for 1 sp.

1 sp. One. Now, add in the new 'echoes of power' idea that they're planning on adding in U9 (iirc). Short answer is this: casters don't run out of mana. Being a caster has nothing, really, to do with resource management.

...Which is why they are upping the costs and the cooldowns for these SLAs... keep up!