The character of Lucifer will be played by Mark Pellegrino (Jacob in Lost). He will first appear in the Season 5 Premiere episode "Sympathy for the Devil" which airs Thursday September 10 at at 9pm on the CW.
Mark Pellegrino has been on the TV show guest star circuit for a while now and he has definetely honed his acting skills. I think that his performance as Lucifer will be memorable to say the least.
Synopsis: Season 5 Episode 1 "Sympathy for the Devil" - Picking up where the finale left off, Dean (Jensen Ackles) and Sam (Jared Padalecki) watch as the Devil (guest star Mark Pellegrino, Lost) emerges from Hell. The brothers and Bobby (Jim Beaver) deal with the aftermath of Lucifer rising and the stunning news from Chuck the Prophet (guest star Rob Benedict) that Castiel (Misha Collins) was blown to bits by the archangels. Robert Singer directed the episode written by Eric Kripke.