Tank: Paladin - Warrior - Dark Knight
DPS (physical): Dragoon - Monk - Samurai
DPS (Magical): Black Mage - Summoner - Red Mage
DPS (support/enminity control/TP-MP regen...): Bard - Machinist - Ninja
Healer: White Mage - Scholar - Astrologian

This is why we are not getting new classes for Healer or Tank in the next expansion.