Every time Blizzard makes any move that might upset the already established Warcraft lore, some players seem to get very, very annoyed. I personally don't grasp the lore well enough to know when Blizzard is putting something in the game that would conflict with some other piece of Warcraft history. Sure, I know why most of the factions do what they do, and the basic outline of the Warcraft universe up to this point, and I like to read the quests to get some further info, but I am by no means an expert.
However, some folks most certainly are. And if the claims of many of the hardcore lore junkies are to be believed, some of the moves Blizzard has made, such as the faction placement and class selection of the new Burning Crusade races, practically ruins the game for them.
Are you a lore junky? Does it send you over the edge when Blizzard makes a game change that totally contradicts the history of Warcraft? Or do you simply not care?