Munn, 30, and Pill, 25, join Jeff Daniels, who will play Will, the co-anchor of a cable news show who must deal with a new team after his fellow host jumps ship for another job and takes most of the staff with him.
Munn will play Sloan, a sexy financial analyst with a show on the same network as Will. Pill will portray one of Will's loyal associate producers involved in a shaky relationship with another staffer on the show.
The project, tentatively titled More As This Story Develops, will be executive-produced by pilot scribe Sorkin, Scott Rudin (The Social Network) and Alan Poul (Swingtown). Superbad director Greg Mottola will helm the pilot.
Munn most recently starred on the short-lived NBC comedy Perfect Couples and currently appears as a correspondent on The Daily Show with Jon Stewart. Pill will next be seen in Woody Allen's new film, Midnight in Paris, which hits theaters this month.