Yes, Powers Boothe plays Cy Tolliver, a rival saloon owner of Al Swearingin.

Also, regarding Wyatt Earp, I saw this posted on another message board:

Quote:
"It's a historical fact that Wyatt Earp came to Deadwood and that Bullock threw Wyatt Earp out of town the next year. Earp came in to try to organize for George Hearst and Bullock beat the s**t out of him. We'll be seeing Earp in the next season." (source: David Milch, quoted in True West Magazine) (A Deadwood rep cautions viewers that Milch could change his mind, and Wyatt Earp may not join the series until the third season.) They will “cast big,” in other words, get a big-name actor to portray Earp.


— Rocky