Yes, the awesomeness that is the swarm of melee toons is why I probably wont be doing arena seriously on my shaman.

Being swarmed as a caster in turret mode was always the way teams really beat me, even when the casters would move in and swarm around me. Mana being an issue is the real reason that melee start to shine, since no melee toon will ever be out of resources, even the ones that use mana.