I'd definitely like to see whips added as a weapon, regardless of class.

I'd like to see a dancer type class, the Ul'dah intro cutscene was very inspiring with them dancing during the parade. The way that mobs are frequently partied and close would make confusion/charm an interesting spell.

I'd also like to see a pet class. It would be interesting if it was like a familiar that was tied to you and grew as you ranked up. So 1-10 it would be an baby/egg and then 10-20 it would be a juvenile and then it would get stronger/older. Either the other commands the player had equipped or its armor would affect their attacks, and perhaps when they grow they could affect how they look.

Chocobo-handler. would be like a DOL, player would have abilities to raise chocobos and perform other chocobo related activities. some of their abilities could be Class-all so that at players who ranked up the job wouldn't need to switch if they wanted to ride etc. Could go on quests involving caring for NPC chocobos.

Gardener.. DOL/ special DOH. players could grow their own plants using various seeds, water and apply certain fertalizers. Lord of the Rings online has a farming mechanic where these were performed in various fields over a short period of time, but having long term gardens in a player owned space would probably be more interesting.