I think the issue right now is that the classes themselves don't always lend themselves to much for variaty in the "Job" section in the future. Gladiator has tank skills, what good what that be for a dark knight? But what sense would it be for it to branch of something strange like Lancer?

I think the class system will only serve to stifle the introduction of new jobs and their abillities.

We will see how they work with it in the future, but I'm personally looking forward to them nixing the class system eventually when the Job system is fleshed out enough. Wether this will happen or not I am not certain but I feel as it stands now the system obviously needs some tweaks and I'm looking forward to what those tweaks end up being.