I'm sure its been mentioned before, but rather than a community fortress, would anyone be interested in setting up an entire world that gets passed back and forth? A world with everything, with plenty of interesting sites and embarkation locations, that we take turns building fortresses/dungeons/deathtraps in, perhaps 10-15 years in game/days out of game out of game (whichever comes first) at a time?
After everybody who wants to builds and abandons their fortress, its redistributed to everyone and we then explore it in adventure mode.
So, would anyone be interested?
Obviously, this would take quite a while to do, but I think it would be great fun to go and explore a whole bunch of other people's forts in a single world.
And obviously, we'd try to minimizing talking about our fortresses - they are meant to be SURPRISES for the other players, and would be built with that in mind as well. After the world is "completed", or at least after it's got a few fortresses running in it, we could start a seperate explore the world thread where people discuss the fortresses that they found and try to figure out who built them, what the point was, etc. (and hopefully the creator can keep quiet).
While thats happening, there's no reason the community world can't keep going either - perhaps released to the adventure thread every 5 or so fortresses?