WHM - More water-based techniques, likely off-GCD.
SCH - Fourth Aetherflow stack and/or offensive technique to apply it.
AST - Card saving / delaying, potential paired card bonuses

PLD - AoE enmity combo finisher after Savage Blade
WAR - Finally get a use for MP
DRK - Dunno, they're still a grey area for me.

BLM - Astral/Umbral stack "eating" for Ley Line bonuses
SMN - That fourth Aetherflow stack is looking pretty good...
BRD - The return of Flaming Arrow
MNK - Greased Lightning stack "eating" for Chakra bonuses, or vice versa
NIN - Cooldown adjustments based on quantity of signs to make one- and two- sign more relevant.
SAM - Frontal positionals. Learn those cleave timings!
RDM - More transition from magic to melee and back again.
DRG - Tough one. They've always been balanced enough to not complain about much after Heavy Thrust was fixed. Dunno.
MCH - Dunno, they're still a grey area for me.
BLU - Moar spells!