After watching the trailer, you can see which set are for some classes :

During Hell's Lid, against the dragon boss you can see a scholar with the white set (previously BRD/MCH in Castrum Abania). Against the "lava boss" you can see a BLM moving with the set from the Highlander Hyur in the middle.

During Fractal footage, the PLD has a feathered headpiece like the lala in the screen.

For the others, my bet are on caster/healer now for NIN and MNK/SAM and the two "plate" stuff for DRG and BRD/MCH.