I feel its a bit sad that unless you yourself choose to become a vampire, the vampire lord class wont be seen after the final battle in Volkihar.
What could have been implemented is that after killing a certain amount of vampires, a vampire lord assassination could become available. But since its not a "pure-blood" as the Volkihars were, it could have an additional weakness in addendum to Anuriels Bow. Namely, werewolves. Giving a werewolf the ability to finish off Vampire lords and maybe vampires in general with an unique finisher could make vampire hunting even more interesting again.