A Smn that would cast all the former summons in all FF including Shiva, Ifrit, Garuda etc! Wait....
No really......
Besides that ehm, Maneater job for PVP >:) "What you want to take me on??" You have been eaten by Monarc.... You lose!
(^o^)/
Seriously: I would like to see dedicated mage types, like Firemage or Thundermage or something. You would have all thunderbased possible spells, like Thunderstrike (Lightning magic def down, Earth Defense up, both castable on enemies and allies), Jolt (Stun), Circumvent (Lightning surrounds you and protects you from 1 magic spell) or Blast (Terror, JA usable every 10 mins), something like that. Add some non-elemental lightning, like with Meteor or Impact and you have a well versed mage.
Yeah, more new jobs and new concepts is something I would like :)