Serenity (spoiler free)

I went to a 1:45 showing of Serenity with a friend today. I thought it odd that it appeared we were among some of the youngest people in the audience (being that we are both in our mid-late 30's). Considering most of the friends I know who are fans are my age or younger, it was worth noting. That, and the theatre was hardly even 1/4 full.

Anyway, we enjoyed the movie and wonder where the story would go from here, if that is even a possibility. Any of the more rabid fans out there have any clues on if this is the last we will see, or if Joss is working on more?