You know, the setting might be interesting to return to, but without the crew of the Serenity. Be more morally grey, the Browncoats deserved to be beaten because they were fighting for the right to exploit others, pollute, and whatnot. The rebels were robber barons and local warlords who used complaints about the core worlds stealing resources with patriotism and “freedom” to motivate the troops.
Have the new storyline be about a relatively new ship from the core worlds, out to find out what the story of River Tam was. Exploring, finding out the sins the Core did a generation ago, finding out that Reavers still exist though they were thought to have been driven to extinction ten years ago, things like that. Give us fresh faces, let the core (hah!) cast be slightly naive so that we discover the Rim through their eyes.
