There is no race specific Dark Urge content. Some races have more dialogue specific choices than others but none of that is specific to the dark urge. I remember pre-launch the belief was that Drows would be the race with some of the most race specific dialogue options but I don't know how true that actually ended up being in the final game nor am I aware of anyone having come up with counter for number of race specific dialogue options for each race in the final game yet either. I wouldn't worry too much about that...just pick a race that suits your class very well.
