So, I'm of two minds on what I would want. On the one hand, like Grav said, I think there are a lot of unresolved things for all the characters that I would like to get closure on. Imp's kids. Gale's changing outlook on self/others/life. Sol's past and alt self. 'Stock's heroic journey (
http://www.thewritersjourney.com/hero's_journey.htm ) especially, since I've always viewed him as kind of the central POV character, and his story as the primary morality play for the game as a whole.
But at the same time, I feel like the characters are pretty big fish on a little world at this point. Serenade and Flare not so much, they are in a good spot to be central characters, but the others are crazy powerful, and will overwhelm many of the more common story paths that tend to pop up in games. That doesn't preclude storytelling with them, but it requires different stories than you would use with other characters. That makes me feel like we should explore some new territory with some other characters.
Personally, I'd like the following:
1) a story thread that advances the plot by several years, maybe even moving us up to the current real-world date (02/2017). Have the primary characters driven to the margins by various personal issues (e.g. Imp didn't become president because he went on a mad hunt for Apostle and to resolve his own storylines; Serenade decided to become THE pop icon for the planet instead of being a full time 2TMer), then see them come back together to fight threats both home-grown (social issues involving aberrants/utopia/terrats/etc.) and external (aliens, reality-hopping novas). This would be the high-power story path, and define how the aberrant war and the following dark times develop.
2) at least one story thread that explores some of the stuff we've only been alluding to the whole time. What's up with all the alternate timeline stuff? Ancient aliens, WTF? I think this would be a good place for some new characters, anything from trinity era psions to daredevil heroes in any era. Maybe take a poll and see what alternate story we can all sort of agree on exploring?
3) Finally, maybe we could do a thread exploring the mirror-verse we've dealt with on several occasions, and what happened there. Why did it get all dark and miserable? How did everyone else turn out? This also has the side effect of letting people "stretch their legs" a bit, in that they don't have to restrain their powers for the sake of setting maintenance. They can go all-out and explore just how abusive high-end novas can be, but in an interesting way.