Barbs were never really nerfed. Back in the 1.3.6 version, like 50 patches ago, they were really underpowered - mediocre damage, low magic defense, crap stun and no antistun. So they got damage boost on their special poleaxe and they received unique rings that refined for magic defense and had additional accuracy bonus. Although these changes made them viable in the 1.3.6, with 1.4.4 they became OP due to this, because of the new 79/100 skills added and genies. Genesis update gave them basically everything what they have been missing and still they had that special poleaxe and rings.
So what was done is lowering the attack on their poleaxe back to the previous state and removal of their special rings. Even after that they are still kinda OP, but not that much as they were.