Geomancer, Do you want it?

[Elexia]

How so? i think Geo's could cast a spell based on the terrain on which they are standing and perhaps weather patterns could increase magic potency or add another spell.

As Shogun basically stated, its mostly the way terrains and atmosphere is being designed in terms of the job itself, but the skill system in XIV/ARR is based around pre-existing skills rather than shifted skills based around terrain/weather. This is why I'm waiting to see how it works in XI with the setup of "pre-existing" skills since it will give a better idea of how SE could improve on it in XIV so we'll have a better base idea to work with.

It's partly why SE said there's no current plans for Blue Mage, since Blue Mage and Geomancer are the two unique mages that tend to have some difficulties in design.