I would love to see some kind of skill tree system similar to WoW,SWTOR, EQ2, or even Borderlands.
Something about having the option to decide what kind of unique abilities/traits I want and being able to have a little control over the recast timers my class/job has and how my character grows really means a lot to me.

More unique classes/jobs.
Summoner
Necromancer
GunBlade user! such a cool weapon that screams Final Fantasy but does not show up in their MMOs