To me, playing through dungeons with a bunch of random people, adpating and learning new fights, or old fights with new people is a lot of fun. I really like playing through dungeons in contrast to grinding quests. Even if it is playing through the same dungeon (although i would like to see more dynamic and random events inside the dungeons).
BUT, right now there is no reward at all for playing dungeons except the small exp you get the first time. Loot doesn't really matter. It doesn't feel like the gear you wear matters much at all anyways.
It would have been great with some sort of reward for re-playing dungeons. Just take a look at other mmos to get some ideas.