Today a guildy induced me to run Heroic Halls of Reflection on my tanking warrior. Sighing, I slapped on my heroic set and we went into the instance (actually, we ran all three ICC heroics) and when we finally got to the Lich King, said guildmate said "Okay, we'll do the ledge strat." I had no idea what the ledge strat entailed, and told him so. He said "go stand over there" and so, bewildered, I did as he asked.
What followed completely trivialized the event. So much so that I'm torn: on the one hand, I hate HoR in no small part due to the difficulty of picking up multiple abominations and tanking them while also trying to get aggro on the spell casting Risen Witch Doctors. The 'ledge' strategy is very simple: let Arthas walk past you and lumber his slow way up the tunnel after Jaina or Sylvanas like he always does. Meanwhile, the hordes of undead he spawns? They come running back to you, even if you're still at the door to the ledge. Since you could never stop the Lich King from getting to Jaina anyway, you don't lose anything for staying behind him, except that you no longer have to adjust in the event that the Lich King is getting closer to you with his aura of hurty.