Dorian's character profile is up!. In it, David Gaider discusses the exiled magister's plan to foil a Tevinter plot, his witty personality and his interactions with other party members, particularly Vivienne.
Dorian is also revealed as being gay, the first "fully gay" character David Gaider has worked on. His "refusal to play along" with the facade of perfection worn by Tevinter magisters causes a rift with his family, and "contributed to his status as a pariah".
Thanks to B.S.S.T for finding the news!