(Oh, my holy fracking gods, that was such a frelling awesome movie!)
I will have lots to say in the way of a review, later, but I'd like to mention something really surprising - stunning, really, about Serenity.
Quickie review: minimal Serenity spoilers - trailer only
First, my very brief review - I'm sure that I'm repeating the same things that many people are saying, but I haven't read any reviews yet.
Joss Whedon has written a memorable, exciting, eye-popping movie with a brilliant premise, clever dialogue, and edge-of-your-seat scenarios. Like the best of his television episodes of Buffy, Angel, and Firefly, the plot hits on all four cylinders, the situations are poignant and involve the viewer. The scenes grab you and shake you so that the film seems to fill 3 or 4 hours, and the story really does make a fitting extension to the TV series, with both provides fans of the show with some closure and imbues neophytes to the Firefly universe with intrigue. Even newcomers to the "space western adventure" genre will find something new and interesting here, I think. There are imports from the Buffyerse and nods to everything from Ridley Scott's Blade Runner to The Matrix and Gibson's finest. More on this in a bit.
All of the characters we've come to know and like or love (or dislike) in the series settle into their familiar personalities. The passage of time, apparently half a year, is marked by the prologue, which tells a suprisingly complete backstory in about ten minutes. A few quick vignettes serve to introduce the villain of the piece, the Alliance Operative.
Slightly more detail - some non-critical spoilers
The new story makes us feel the heft of the new inhabited system and its cultures. The "virtual classroom" prologue fills in an important missing piece: the scope of the Firefly universe. The series never quite specified (though Joss has explained in interviews) why there are so many accessible, habitable planets in a galaxy with no FTL, and why the Terran system is nowhere in the story. Even the human diaspora is shown in this brief flashback.
Mal's fences, his hideouts, and a new ally of Serenity's crew, the archetypal hacker Mister Universe, are all introduced quickly and efficiently. The landing on the "secret" Alliance planet and the whole Aliens/Resident Evil/DOOM/Quake plotline could have been a real clinker, especially since the big revelation is hard not to see coming, but the macabre treatment that Joss gives is both tense and disturbing. I'm sure some will disagree, but Summer Glau's acting is right on the money in this film.
As you might expect, the film is slightly darker in tone than the television series, and not just because it features a tremendously skilled assassin and depicts the Reavers in all their terrifying detail. The film puts much more at stake for the characters than their own lives, and gives them, their adventure, and their sacrifices a lot more purpose in the world thereby. That's something very striking about a story that has been very much about a ragtag band of fugutives living a hand-to-mouth existence on the "wild frontier" of known space.
The following commentary contains major spoilers for the Firefly movie, Serenity, and mild ones for Dan Simmons' Hyperion/Endymion universe.
If you haven't seen Serenity, see it first. If you aren't sure what I am referring to in any point below, justhuman wrote an excellent synopsis and critique. On to my commentary...
I can't help feeling that I've just watched a preliminary version of Endymion and The Rise of Endymion!
Consider the following parallels:
Mal Reynolds: Raul Endymion - The Homeric combat scenes are especially evocative of this.
The Operative: Rhadamanth Nemes
River: Aenea (sans the romance angle) - Archetypally, she's a holy innocent. She's also an incredible threat to the superpower because of the knowledge she carries within her, something that might awaken at any moment, hence the need to apprehend or kill her right away.
"World Without Sin": Lenar Hoyt's corrupted mission
Organizations and Political Entities
Reavers: Ouster Marauders
Alliance: The Hegemony of Man / The Pax
Alliance Parliament: The Pax
Sinister powers that be that pull the strings of the Alliance: The TechnoCore
Independents: Hegemony rebels on Maui-Covenant
Browncoats: Siri loyalists on Maui-Covenant
Ships and Technology
Serenity: the Consul's singleship, used by Raul and Aenea - OK, Serenity doesn't have an FTL drive as the ships of the Hyperion/Endymion universe do, but the ships share a lot of common points. Did you notice that Serenity even gets lanced with a Reaver CPB (coherent photonic beam) as it's coming down?
The Operative's dropship: Rhadamanth Nemes's dropship
Vera: Fehdman Kassad's high-powered rifle, the flechette rifles on the Consul's ship that were used by Raul Endymion
Alliance English/Chinese: Web English (replete with Japanese loanwords)
Earth-That-Was: pre-Hegira Earth
Earth got used up: The Big Mistake of Ought-Eight
The exodus from Earth: the Hegira
Colonization and terraforming of Core Alliance Worlds: Colonization and terraforming of Core Hegemony Worlds
Reestablishment of human civilization and rise of the Alliance: Formation of the Hegemony and rise of the Pax
Alliance atrocities against colonists on Miranda: Core atrocities against colonists on Qom-Riyadh
Creation of the Reavers from the Miranda colonists using the Pax: genetic engineering of the Ousters from Earth-born humans
Browncoat defeat by the Alliance: quashing of Maui-Covenant rebellion by the Hegemony
Browncoat leaders going underground after the war: Siri and Merin's and grandson (the Consul) being a closet independent
Broad discretionary powers of Alliance operatives: Broad discretionary powers of Pax fleet and Pax Inquisitors (as secret police)
Events in the Story
Mal, Zoe, River and Jayne fleeing the Reavers on Serenity's flier: Raul's hawking mat rescue of Aenea on Hyperion and his duel on Mare Infinitus
The Alliance devastation of Haven: the Hegemony devastation of God's Grove
Murder of Shepherd Book on Haven by the Operative: Murder of the priest who sheltered Aenea and Raul on the arctic planet Sol Draconi Septem, by Rhadamanth Nemes
Discovery of uncounted numbers of bodies in the abandoned Alliance colony on Miranda: Discovery of uncounted numbers of bodies in the Labyrinth of Hyperion
The massive Alliance-Reaver battle: the final pre-Fall Hegemony battle in The Fall of Hyperion / Father Captain de Soya's defection / the invasion of the startree in The Rise of Endymion
Wash's death: Father Captain de Soya's being shot out of the sky over Tien Shan
The final confrontation at Mister Universe's complex: the final confrontation on Pacem
Mal's duel with the Operative: Raul's duel with Nemes on Tien Shan
Mal's broadcast: okay, I know there is no way there can be a fundamental parallel to the Shared Moment, for all its grandeur and spiritual impact; but the political effect (while not entire) is similar - "you won't [see me again] there is nothing left to see", says the Operative, ultimately defeated just as the Nemes clones and the Core were
Edit, 10:55 CST - I might have forgotten to mention that I'm a grizzled old Browncoat, though I may not look it. I watched the show religiously during its regular run (missing only one ep of the 11 that aired, IIRC), and I used to post to USENET about it.