The urge came up to write this out, so here goes:

Druid: Transform into animals in order to kill other animals. You know, to "maintain the balance of nature."

Shaman: Throw little sticks in the ground to do the heavy lifting.

Hunter: Send your tamed pet out to get killed and hope that Warrior doesn't run straight at you.

Mage: Run around dangerous battlefields wearing only cloth and use energies that twist the minds and bodies of longer-lived races.

Paladin: Wear heavy armor, heal and buff people, and throw up a shield when the other player thinks they're about to win.

Priest: Much the same as Mage, only less offensive ability, but better healing than Paladins.

Rogue: Go invisible. Stun, stab, and poison, then run away and hide if you mess up.

Warlock: Same as Hunter, only with demons. Also, if anyone with a big sword and heavy armor so much as looks at you, you use fear.

Warrior: Run up. Stab. Rend, tear, hamstring, and execute. Keep off cloth-wearers. Hope the cloth-wearers remember that your being alive keeps them that way.