As a new class/job I would see Elementalist/Shaman as a melee type with elemental based buffs and debuffs.
They would dual weild daggers and wear light armor. They can fill up the role of an off-tank with earth based spells similar to stoneskin and other spells to mitigate damage. They can also buff the party with elemental armors, spells that add elemental proprieties to weapons etc. They could also debuff mobs with spells like ivy that slow movement or stall the enemy and DOT spells.
They could use TP based attacks too.
You start off as Shaman and the job is elementalist.
Req: 30 Shaman, 15 conj, 15 thau
What you guys think?
EDIT: Something like this http://finalfantasy.wikia.com/wiki/Geomancer_%28Final_Fantasy_Tactics%29
Thanks to KoujiGeki.