When I first started playing WoW, I read every quest. I was a newbie who didn't know where anything was and didn't even know of the existence of addons to help me in my questing. So I often searched the quest text for clues about where to find mobs and items. As my game savvy increased, I read the quests less and less, until finally I didn't read them at all but rather clicked on my map to see where I needed to go and what I needed to kill.
Now, I find myself slowing down again. The lore is interesting to me, and more and more, I realize how expansive the world is and how fun it is to participate in that world. I am not an RPer by any account, but I find myself wanting WoW to be a world and not just a game.
Out of a desire to understand and enjoy the lore, some players have read Arthas: Rise of the Lich King, The Shattering, and other WoW / Warcraft-related books. Other players have absolutely no desire to know the lore and view WoW as a game that they enjoy playing -- not a live-action fantasy novel.
Are you the sort of player who loves the lore? Or do you just play for the game action?