So Blizzard just announced that they have 10 million subscribers. That is not a small number. At all.
I ran Shattered Halls on Heroic late last night. It was a great run, as I was able to finish my Trials of the Naaru quest for the zone. We ended up disenchanting The Bladefist. We ran with a Protection Paladin, a Retribution Paladin, Holy Priest, Mage, and myself. And it was great. We finished the instance with tons of time left over on the quest timer.