I find it highly unlikely that aggro decks would use this card. It's a 5 mana 5/5 that does nothing against 6 out of the 8 classes, and an aggro deck wouldn't leave any armor to strip anyway. It's simply not good enough a card to be run except as a specific counter to extreme amounts of armor.
The one case where it could be problematic is for Combo decks that are dealing 30-ish damage to the face. Even then, running this as a counter to only 1 or 2 classes seems a bit iffy for ladder. Especially since you typically can't use this card AND nuke for 30 in a single turn, meaning that the Druid or Warrior can play around it by holding armor cards for the post-Platebreaker turn.
My prediction: Sees no play at all this expansion, and shows up only as a tech card in tournament play in future expansions.