Vampires and Werewolfs
It's quite obvious that vampires are the concentration of Dawnguard, and the developers have spared no expense creating the ultimate vampire lord for the Dragonborn to transform into. The transformation occurs in a similar fashion to that of werewolfs, although the player can change back from a vampire lord at will. New powers for the lord include hovering (presumably to increase speed), summoning a gargoyle, bats that attack anyone in melee range and a powerful paralysis spell shown in the trailer. Also, the expansion introduces the ability to bite people on the move and even during combat. Unfortunately, the player cannot be both a werewolf and a vampire (although there is an option to regain lycanthropy at a later date). However, to make up for players who would rather stick with howling at a full moon rather than blocking out the sky completely, a skill tree for werewolves has been introduced. Abilities include enhanced health, stamina, feeding and the ability to summon a werewolf for aid.