Yeah, FFXI had some great classes. I always want a Blue Mage class, but I don't know how they could do it better than they did in FFXI. BLU is the best.

Perhaps they can combine some classes, like Thief/Ninja that was already mentioned. It would be cool to see a class steal a weapon off an enemy and then throw it right back at them!

Also combine Summoner and Beastmaster to create the ultimate pet class. You have your own pet that levels up with you and you can choose what abilities it learns and uses in battle, without the restriction of mp. That would totally be my choice if it was offered.