You're sorta right, but slightly misled. Every single bear has had their armour buffed. That is without question.
It depends on whether you notice it because of the ghosted PotP talent if you even notice it. 2 situations:
-You were a bear at the time of the shattering, you had +12% damage reduction +6% AP through Cataclysm. Now that has been removed and since we all have the Armour buff, you take net 12% more spell damage but less overall physical damage. Your threat is slightly nerfed.
-You weren't a bear at the time of the shattering, since Cataclysm hit, you have been taking 'intended' damage. The ghost talent was removed, but it has no effect since you didn't have it anyway, therefore your net gain is +Armour and you will be taking the same net amount of Spell Damage but less net Physical. Your threat is the same.
Full post at:
http://theincbear.com/thick-hide-theorycraft/
Feel free to correct me if i'm wrong