I havent looked indepth into guild wars 2 quest system but in this video they talk about how they want the player to feel more important and that things will change once you complete the quest and will stay changed for you
http://www.youtube.com/w…
According to my friend who has some knowledge of the table top: Dark Millineum is the rule book (Or whatever they are called in the table top world) before they added Tau and Necron. I dont recall if he said Eldar and Dark Eldar were included in that