Well, the best bit of details I can give are these;
- The first episode is an hour and a half, without adverts, ie movie length. The emmy it won for special effects is well deserved - the first episode really does look and feel like a full blown movie.
- The series opens with a flash back to the 'Battle of Serenity Valley', where we see the captain and Zoey fighting for their lifes. The backplot goes that there was a war between the independants (our characters, poor, on their own in space) and the Alliance (think high tech, rich etc). It's very American Civil warish, except presented in an enjoyable fashion.
- Flick to 5 years down the line, war is over, independants lost. Those that remained alive scattered across to "border worlds" - the outside - and struggle to survive outside the system.
- A few back plot episodes show us how the ship ("Serenity" - also the name of the motion picture due to release next year) was formed, the crew etc.
- One of the characters is a priest, one is a whore... There's themes about loosing your faith in everything, themes of family, themes of sex, themes of faithfulness... Everything.
- There's romantic interests between the characters (of course), and both of these "could be" relationships are played very well.
- There's a character called Kaylee, who is the most lovable TV character ever, equal to Willow. Kind of person you just want to pick up and hug to death.
- There's guns. No lasers - too much of that in Star Trek. People can afford revolvers. Yes, western guns. There's sex scenes. There's crime. There's death. There's bag loads of emotion.
Sound like Trek? Nah. It's a Whedon programme. It gets under your skin, and invades your dreams after a while - when you finish the DVDs, you will sit and go "I NEED to know what happens!". There's so much set up about everything that's happening, you can tell things are happening for a reason, why the characters have formed on that particular space ship, why there's the history of the war etc.
And then - you have the film to look forward to. It's going to be huge. Oh yes. Also, Joss's first time directing a film.