Prot pally tanks Onyxia -
It's hard to see what he's doing, but he's holding aggro by spamming Greater Blessing of Kings. Which, since it applies to all members of a specific CLASS, not even just a party, is even more insane than the Battle Shout semi-cheese we used to kill Nefarian back in the day. Hard to believe nobody tried this back in the day.
If Blizz leaves this in the game, it seems like prot paladins just suddenly rocketed to the top of the list for raid tanking.