I have to agree with Noiseboy here a bit. Went to see serenity the other night, and while it was an OK film, it never made me go wow. Now most of my mates are fellow computing graduates, so the film has been hyped up to me something rotten over the last few weeks, howeve, in my opinion I found the plot to be weak and the acting to be ok but not fantastic (although the girl who plays river wasn't bad).
All in all I think it could have been a good movie, it was just too long. If the story was either focused on Miranda or River I think it could have worked alot better, it just seemed the writers tried to do too much in the space of one film and ended up just making the whole thing drag out.
To sum it up, I walked out the cinema saying to my girlfriend "That could have made a decent tv prog, but bit long for a movie". That was before I had even heard of firefly.