Spent last night discussing how Firefly could be revived in the aftermath of Serenity, and considering the long time since the series ended. We decided that the only option would be to focus on new characters. Then came the discussion about what the new plot line would be. We decided that it would be interesting to see the aftermath of Miranda; the rebuilding of a new Alliance.
It lead to a lot of talking, but we decided on a few things. It would be set roughly 20 years after Serenity. The new main characters would be a crew of law-enforcement officers working for the Alliance, somewhat similar in function to the modern-day FBI.
A new Independence movement would have arisen, although this one more of a terrorist movement than a military. This time these new 'Browncoats' (a name offensive to the original Browncoats) would be the villains.
We also talked about what happened to the Serenity crew.
Inara died after a short, but happy time with Mal.
Jayne settled down, found some peace and became the mayor of Canton.
Simon and Kaylee settled on an outer-rim planet, got married and had a bunch of babies.
River became the new president of the Alliance, working hard to build a better one.
Zoe works at the leader of the new Alliance navy.
Mal is still a smuggler. He lost his faith at Serenity Valley and his love when Inara died. Now he's just a sad man in a haunted ship, living outside of the light.
Zoe had Wash's child. Their daughter has run away from the stifling life of the central planets to join her Uncle Mal on his ship.