A little part of my interest in this game, and a part of my soul has been dying every week I've seen a Shaman, Warrior, or Mage class set drop from Blackwing Lair except for mine. In those eight weeks I've farmed, I swear, I've seen every single Tier 2 piece drop except the Paladin class specific pieces.
12% isn't such a small drop rate, but it's really irritating because it belongs to such a massive loot table. You would think that since Classic Raids are usually 40 man, you'd see twice the amount of loot drop in comparison to a 10 man raid. Guess that's a silly misconception.
Now, I'd suggest increasing the drop rate, but everyone will just say "Quit crying, you'll get it eventually."
I won't be playing this game forever, Blizzard. I really won't.
* Edited to correct drop rate *