Do you still have humanoid "player characters" in your game, or is your avatar simply a [set of] ships? I've always wished for a space game where each "ship" is a thriving colony all on its own, with hundreds of players with their own quarters, and an intense rivalry over who will be "captain", "navigator" and so on (unless it's some sort of military ship, but there could still be a mutiny!) If you are the ship[s], this gets a little less poignant.

Also, watching sci-fi TV shows for a long time, I've come to appreciate the visual value of "away missions"/shore-leave. It's boring staring at a starfield for hours at a time (even with cool nebular effects.) Is there a way to land on planets that have life on them (that is, not boring ol' asteroids) and perhaps stay there, living off the land for a while where no one can find you but for your radio pollution?

Sorry if this is all irrelevant to your particular implementation, but I've been planning my own similar venture for a while.