Jeff Fahey as Russell (unconfirmed), a brilliant scientist who's "capable of great insights and has a tremendous knowledge across various scientific fields." Unfortunately, he's very direct and lacks people skills. Russell is also very interested in magic and mystery, despite working in a scientific realm.
Ken Leung as Unknown. Leung, who starred in X-Men III (he's the guy with the spikes growing out of his face), is definitely in season 4, but rumour has it that only producers Damon Lindelof and Carlton Cuse know exactly who he'll be playing...
Lance Reddick as Arthur Stevens, a ruthless corporate recruiter. Reddick will be a familiar face to fans of Oz and Law & Order.
Rebecca Mader as Charlotte, a naturally attractive and athletic woman in her late-20s. She's a successful academic with a precocious and funny nature, but hides it behind a tough exterior. Charlotte is a recurring character who may become a series regular in season 5. British actress Mader is best known for roles in The Devil Wears Prada and Hitch.
Jeremy Davies as Unknown. He will appear in 8 of season 4's 16 episodes. You may remember Davies from the films Solaris and Saving Private Ryan (he was the German linguist.)
Andrea Roth as Unknown. The former Rescue Me star will have a recurring role, rumoured to be a therapist.
Fisher Stevens as Minkowski. The actor, most famous for playing Benjamin in the Short Circuit movies, has been revealed as Minkowski -- the voice Jack speaks to on the satellite phone in season 3's finale
Zoe Bell as Unknown. The stuntwoman, most famous for portraying Lucy Lawless and Uma Thurman in action scenes, as well as starring in Death Proof, now has a recurring role in season 4.It's not known if all of these new characters will be on the supposed "rescue boat" heading to the island, or if they are as-yet-unseen members of the Others. A few could even be recurring characters in flashbacks! Who knows....
But I'll have more details as and when...
