2nd Jobs I'd like to see:

Gladiator -> Dark Knight - I'd really like to see a Cecil style Dark Knight instead of a Scythe Dark Knight. I know a lot of people would disagree though.

Monk -> Dancer - Dancer's in FF were pretty good with Hand-to-Hand, and I feel like martial arts and dancing have a decent amount of similarities. Would love to see them as a healer.

Lancer -> Templar - It'd be great if this was a Tank. Thematically, it could be like Templar from FFT, using status effect based attacks.

Warrior -> Berserker or Beastmaster - I'd love Beastmaster, but Berserker would be good too. Either way a DPS.

Archer -> Ranger - /obvious

Conjurer -> Geomancer - I feel like this is obvious too, though I'd want to see it as a full DPS. I'd hate to see Conjurer get shafted in the solo department by being given another low damage Job.

Thaumaturge -> Time Mage - I'd love to see this, but don't know how likely it would be. If they added a Support role, I'd see it as that. If not, it would be kind of cool as a Healer. =x

Oh, and for Musketeer, I'd love to see Corsair (DPS) and Chemist, ala FFT (Healer).