It's terrible when it happens because until the 15mins ? passes you have two choices, Carry them or leave yourself and get a queuing debuff. My gripe is no one is forced to learn anymore, the random queue rewards people who can't be arsed to take pride in gemming, enchanting or even learning to get beyond the basic 2k dps we managed perfectly fine on release week.
I have been working on my paladin healer in heroics, havent played it since tbc raiding days and decided to level it up. Pretty decent performance on him despite my gear at the time, I had two dps pulling 400dps, a tank in acceptable gear, the other dpser pulling about 2.5k. I had to beg the tank not to pull two - four mob packs at a time because the combat would feking drag on for ages causing me to just burn mana.
Marking targets, coordinating CC, and *most importantly*, pulling responsibly so that 9 elites didn't rush us and wipe the party, this Is something I have missed since nov 08.