I'm not a big fan of race/class specific things. I've always hated when games say you can't have certain race/class combinations. Like, "Dwarves can't be mages! They're not magically enough!" ...It's annoying. Having race/class specific quests seems similar to me.
It would make sense for some NPCs to respond differently to different races/classes, but... It wouldn't really add anything to the game, and it would be much fun. I wouldn't mind, though, so I guess that's just a "Does it seem like a good idea?" thing. Also, it would most likely delay the release, if it wasn't already implemented, so I can't say that I'd really like it.
Anyway, good question, Div. I don't know why people seem to have ignored it.