Once you do, a scholar will mention that an earthwuake happened way down the south. The new locations is an undersea trench, located just below the Town of Mirages.

Gladiator is a physical class with moderate stats and the ability to use all physical weapons (ninja knives, katanas, broadswords, bows, everything but staffs and maces). Their special ability is !Finisher, which will either fail, do a critical hit (2x damage), or will hit weak points to do massive damage. The massive damage is 9999pts of elemental damage. The element is dependant on which character you use it with, Bartz has Fire for example (I think). However it fails too often to be useful, especially against bosses. Once mastered, they can use a Blade blitz command, which attacks every opponent - for pathetic damage.
These guys will also attract more random fights, an ability that can be unlocked as you level up the job.

Oracle is a class that can condemn enemies to various fates. This manifests in spells being cast on the opponents after a certain amount of time after condemning. This is almost completely useless as a) they often fail at doing it and b) most of these condemns are too weak or take too much time. Say, 20 seconds for something akin to Bolt2. Doom is the only useful one I saw (certain kill in 10 secs), but again, the actual condemning takes too much time, especially so late in the game when you already have access to more devestating attacks.

Cannoners look like french navy personell from the Napoleon era, and they can, uh, use a cannon to attack. The cannons seem to do more damage then regular attacks by a small margin, but I also saw them doing criticals as often as Monks do (which is very often), and rarely they will also instant kill some enemies (usually ones that would come close to being killed anyway). You can also buy 3 kinds of ammo for these and mix them with a bunch of stuff, but I didnt look into this yet.