Beyond Forster, new cast members include Ashley Judd, Tom Sizemore, Naomi Watts, Amanda Seyfried, Robert Knepper and James Belushi (possibly as brothers), Balthazar Getty, Grant Goodeve, Larry Clarke, and Caleb Landry Jones. Also rumored for the call sheet are Bailey Chase, Patrick Fischler, David Dastmalchian, Ana de la Reguera, Hugh Dillon, and Angela Andrews. There's been no official word yet who any of these actors are playing, though that quickly redacted IMDb report suggested Seyfried is playing a member of the Briggs family.
Jennifer Jason Leigh is involved, possibly as "Judy," a much-speculated-about character who may be a relative of Josie Packard, and/or an early victim of Killer Bob or an alias for Laura Palmer -- referenced by Bowie's Agent Jeffries in Fire Walk With Me ("We're not going to talk about Judy").
Frequent Lynch collaborator Laura Dern is joining the cast as well, with rumors circulating that she's playing the previously unseen "Diane" -- the woman to whom all of Coop's tape-recorded memos are addressed. If true, that would put an end to the longtime fan theory that Diane was a figment of Cooper's imagination.
Many music-world luminaries will also take up residence in Twin Peaks, as we've heard word that Eddie Vedder, Sky Ferreira, Sharon Van Etten, Trent Reznor, and Ruth Radelet of the Chromatics are on the cast list.