I noticed that when the film was officially announced by Universal 2-3 weeks ago, that 2 cast members were not listed:

Alan Tudyuk: Wash
Ron Glass: Shepherd Book

Has anyone heard if these guys have signed on yet?

I came across an apparent casting call sheet on a fansite, http://www.browncoats.com/movie1.html (thanks to cinescape.com), that does list everyone but Book but who knows if this is real or not.

My wife and I are just wondering if there has been any official word on the remaining cast members.

Web buzz is that they both have verbally committed and are just waiting for current contractual obligations to run out before going official.