I am not sure if this will be the official Vampire Lord perk tree when the Dawnguard DLC is released. Everything in quotations are what I have heard from the video.

(Link to source down below)

Vampire Lord Perk Tree-

Power of the Grave: 50 point bonus to health, magicka, and stamina as a Vampire Lord

Vampiric Grip: Can pull a creature to you from a distance, and do chocking damage once it's close. (I heard you can throw the victim once they are drawn in)

Unearthly Will: Night Powers and Blood Magic cost 33% less

Blood Healing: Killing a person with a power attack bite restores all your health

Summon Gargoyle: "Conjure up some help in battle with these menacing monsters"

Corpse Curse: "Paralyse your foe with a magical blast"

Detect All Creatures: "A vampire that wants to live long should stay aware of his surroundings"

Mist Form: "Turn into an invernable cloud of mist while you regenerate your health, magicka, and stamina"

Supernatural Reflexes: "Allows you to move in for a kill quickly while the enemies move sluggishly"

Poison Talons: "Melee attacks now deal 20 points of poison damage"

Night Glow: "A shroud of bats feed on enemies within melée range"

http://www.youtube.com/watch?v=Cv23p_ZFBB8&feature=plcp