Blizzard is pretty stubbornly committed to quality -- not only do they notoriously release things "when they're done," but if something doesn't work they apparently are happy to trash it completely (see Starcraft: Ghost). It is amusing, too, that Rob Pardo says he and Frank Pearce are trying to make "great entertainment projects, not perfect ones." WoW has its bugs, sure, but when you look at Blizzard's catalog: Diablo, Starcraft, Warcraft, you have to wonder what a "perfect" game looks like in Pardo's mind. Those are about as perfect as they come.
And they "eat their own dog food," too: J. Allen Brack apparently spends four hours a night (up to 15 hours a week) playing the game on his own time at home. Seems like it would be tough for other companies to pull these strategies into their own plan (Blizzard really releases one-of-a-kind products), but as consumers, it's neat to get another look into the way they work.