At this point I am on the pessimist side. Yes the game is a lot better, yes there is a fan base that really likes the game but at the end of the story we are too few probably.
Anyway my suggestion is to at least keep one, if possible two people still involved with the community via these forums, tweeter, reddit etc. It wouldn't need to be a high valued developer or anything so the investment would be minimum. The community will feel a bit more engaged and in case Pdx decides to continue the life cycle of the game this "community manager" could promote ideas and the overall view of the community to the new team. I cannot see a big downside for Pdx to do this. It is very clear that the game is at a "maybe we will continue development phase" so you are not creating expectations or anything (I would like to thank you for your honesty on this btw).
So yeah that is basically it hire, keep a community manager for imperator till you figure out what you want to do.