A comment on Kill Ten Rats caught my eye:
But I think there’s more to the problem of quest text than just that people are too lazy to read it and too stupid to understand it. Yes, that’s the basic problem for a lot of people, but quest text seems to me to also be a very awkward game mechanic.
What other ways could it be done? Back in EQ (or was it UO?) you'd interact with the NPC via typed dialog - you'd type something, he'd reply, you'd hope you used the correct keywords, and on it goes.
So here's an idea, inspired by the flavour responses that WoW NPCs have when you just click on them (a sequence of greetings deteriorating into annoyance) ... click the NPC and he mentions he wants help, click again to find out more, and so on. Mix it up a little bit so players don't just spamclick - have the NPC ask a question at some point, to which the player could /agree or /disagree or some other /emote as appropriate. The responses would probably be via text, not voice effects, simply because of the massive volume of content required.
The NPC might react differently depending on if you are mounted or not, right in front of them or not, and so on. Not mysterioius-different, but flavour-different. Some might insist you sit down before they talk, rather than flapping away