Big, big difference between what Gearbox did and what WoW has done.
Gearbox showed us beautiful demos of a game that looked like something from HD heaven, then quietly shipped a buggy, low-definition piece of crap that was essentially scrapped together by 3 or 4 different studios. At NO point did they mention 'hey, we've had to scale back the graphics, the sound, the... well, everything. That game we showed you is pretty much gone, replaced by something that wouldn't have impressed 10 years ago, let alone now."
Blizz is at least forthcoming about their changes. They say 'hey, this is being changed. This is being held back until a later patch.'
Yeah, some of their changes suck. But at least we're told. Nothing at all like Gearbox's debacle with A:CM.