Sam Waterston

Law & Order's Sam Waterston has joined the cast of Aaron Sorkin's HBO pilot, TVLine.com reports.

Olivia Munn, Alison Pill sign on for Aaron Sorkin's HBO pilot

The series stars Jeff Daniels as 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. Waterston will play his boss.

Olivia Munn and Alison Pill were recently added to the cast as a sexy financial analyst and an associate producer on Will's show, respectively.

Jeff Daniels in talks to star in Aaron Sorkin's HBO pilot

The project, tentatively titled More As This Story Develops, will be executive-produced by Sorkin, Scott Rudin (The Social Network) and Alan Poul (Swingtown). Superbad director Greg Mottola will helm the pilot.