A very large portion of us are guilty of it, many people even go into the next expansions saying, "I'm going to actually read the quest text this time!" but then an hour or so into the new zones, it again becomes a race to gather the quests as fast as possible with no regard to the quest text itself.
What if we could have the quest text read to us as we went out into the open world to complete the quests? Personally, when I'm playing, I either have my own background music playing or just have the game's music and sound, so I wouldn't be losing anything from hearing the quest text read like an audio book. It won't slow down the play of the game because I can get in and out of towns just as fast, but the 30-60 seconds it takes to travel to the quest area can be spent listening to the reasons why I'm headed there in the first place.
Whadya guys think? Sure it takes resources and game file size etc, but it could totally add to the leveling experience. Make it optional and I think everyone will stay happy.