Calling it, next DPS Melee class: Soldier

[Grogin]

Considering Dark Knights in previous incarnations of Final Fantasy has wielded different weapons depending on the game entry (Usually a Great Sword, Scythe, or Great Axe), Maurader will probably be the base job for DRK. They will probably have a job specific ability that is the exact opposite of Warrior's Definace, increasing attack power at the cost of health or defense. They may also get abilities that lower enmity (since marauder generates a lot of enmity), and, since Marauder has bloodbath, Storm's Path and Mercy Stroke, change these to take health from the DRK and inflict it as damage on the target.

The most likely next CLASS with either be the musketeer that Yoshi has actually talked about conceptually, or a class that will grow into a thief (Called pickpocket or something similar). Of course they can also add jobs without adding classes, though this brings up other questions about how people are going to learn to play the new jobs.