Serenity kicks ass.
Just a whole lot of serious ass-kicking going on there. I mean Orson Scott Card basically called Serenity the best scifi movie ever. He said that if he ever did let Hollywood do Ender's Game, he wants it to be as good as Serenity, or not done at all.
The DVDs of the series and film are selling extremely well. I think it's very likely we'll see either another season of the series picked up by SciFi or Fox, or some straight to DVD movies. After seeing what Whedon's done with it so far, it would definitely be a blind buy for me.