I should note this review of Serenity before it disappears.

Have Gun, Will Space Travel :

... does it play to the nonbeliever for whom a Firefly is but a beetle whose ass flares and fades in the nighttime sky?

Pretty much, yeah. During one preview screening, a colleague who'd never seen the show -- a campy-quirky take on John Ford's Stagecoach, set 500 years in a future run by the Alliance, which isn't to be confused with the Empire or the Federation -- leaned over and asked, "Was the show this good?" He needed no backstory about such things as Browncoats and Reavers, nor any belabored character development. After all, Serenity does nothing new: It's but a witty, engaging hodgepodge of archetypes and clichés; it retreads not only the TV show's story lines but also those of every Star Trek and Gunsmoke episode. It needed the room of a big screen just to fit all of its influences into a single place.