Here's a recent interview that comes to mind where "new jobs" are mentioned.
Link
GE: what about new jobs or classes, or other changes to battle system.
Yoshida: [Zips his lips shut] We will definitely be adding more actions and abilities for the current jobs, especially because of the addition of the new PvP gameplay. That will require all new types of crowd-control,buffing and debuffing actions. We will tell you more about this system around when beta comes out.