Understood and interesting, but hard to achieve. With more people and ideas involved, it is going to get even more complicated and hard to keep track on.
What do you do when you want to keep track on things? You use a program and settle them into a lawful structure. Here's my suggestion..
1: Let us create one big badass world first of all. It has the option to have guilds, members, artisans, cities, citizens, soldiers, whatever, whenever. These things doent happen suddenly. We need time.
2: Then make a web page: A map appears where you can see the whole place, click on names of places, their buildings, etc.. there would be a membership option for this web page so that people can see locations private only to them. Just like real lifem you will acquire the knowledge of places and things.
3: One could be a carpenter, a hero, scientist, druid, god or whatever. Depends on your stats and patience if playing d&d style, on your ambition and acting ability if theatre style. An away button when you are not participating where you list regular actions and receive messages while you are not around. Every member would have a record of their last locations, what they are up to, their level and so on, etc.. If you want D&D style, random events create treasure and monsters to gain exp, if not, level is gained through actions and social status.
4: People may trade things, for example to create a house in the city map or construct a ship.. and wow.. we will start from an agricultral society with nothing to cityhood!! isnt this cool??
5: after achieving so far, the rest is left to people's imagination. choosing a major, entriques, villainhood and getting away with it, weehee...
Does not sound easy for one person to make, but there are people I am sure who would like to help, including me. I dont want copyright, but I think this idea puts things into the way you want. Obviously, what you asked for was hard, but not unimaginable.
-hellion, THE
also, interactive chatting and a nice structure of chat rooms will be neccessary of course. I estimate about one gig space for the whole information. For example something like:
That region+ coordinates// this cave// this side//
or
This city(you have to be in that country to go here)// that building(likewise)// that floor// this room//
could be the name of the room you are in, and can be used to avoid complications of any kind. puts logic into the thing. There, for example, you could be speaking to someone in private and so on.
I hope I am not wasting server space for uninteresting ideas..
-hellion, THE
Again, I'm seeing people suggest what is already here. We have a big badass world. It has the options suggested. It has its own homepage including a clickable map (yes, it *is* clickable!). We don't have levels for characters, because frankly, I think it's dumb and hard to interpret in writing a story. Like Shadow said elsewhere, we want to stay away from "stats."
But if you wanted to go ahead and bulid a new world, feel free. You'll need to get someone to draw a map, and I figure that will be harder than it sounds. Thrakkiss has been exceptionally kind in providing us several maps for the current world, and as I understand it does not have the time now to do much drawing or writing. If he did, he'd be adding his own chaos to the current RPM destruction story, and I wouldn't be probably screwing up his characterization immensely. 
Yeah, Thrak's character is kind of hard to play. ;)
Anyway, I like some of these ideas. It sounds like your almost suggesting a whole rping web-program. Private map areas. Intriguing.
Not sure that I have the time and ability as a programmer to create something quite as complex as an actual program for facilitating this world, but it's certainly an idea to keep in mind should the time arise. Parts might be implemented here and there.
It's interesting what you mentioned in 3) about D&D vs. Theatrical style. I've always felt that characters in the current RPM advanced based on exactly those two ideas: ambition and "acting" (or writing) talent. People like that tend to gain respect, and thus their actions are more readily accepted. But that's really a side note.
i had a big response to this, then aol kicked me off, twice, but ill try again.
we should steer away from dnd and go for a more storytelling sense. and without stats, you can say that your character is strong and weak in different areas. for example:
the dwarf, fereno, has a personality that jumps at you, unlike most of his race. his intelligence is also amzingly high for a dwarf, while havng no common sense.
i just described 3 stats with words instead of numbers. its much funner to do it that way, trust me.
also, the world can be big if needed, but at first, and for the most part later on, we are gonna have to restrict ourselves to a certain area, like farun in forgotten realms, but smaller.
also, elro, i think he means, the map has click through but goes down to the buildings in the cities, so we know what is around eveything. it will help from people from getting confused. i like this idea.
I know what he was referring to. I was referring to what we already have. What he suggests requires two things:
1. An artist with enough talent to do decent maps (Thrakkiss is amazing, but I doubt he'd do one nowadays) and the time in which to draw them, scan them, and give them to the proper people to post them.
2. Someone willing to take those maps and do the ungodly task of making clickable image maps (probably not hard these days with a billion programs to do it - I do it the hard way by handcoding. and also the time to do this. Shadow I'm sure can salvage enough time to make a "homepage" with some relevant information, but until you actually take the time to try to maintain something like these maps, you don't realize the amount of work required to continually update them as new places are generated.
People are lazy. If there's no motivation, shit doesn't get done. If it weren't for people like me and Shadow saying "Hey, shit needs to get done," and actually *doing* stuff about it by setting up this pseudo-mill and helping commenting on ideas, shit wouldn't be done. The measure of our care for the current Role Playing Mill is reflected in our efforts to find a way to rejuvenate it.
well, ive got a program caled dungeon crafter. its easy to use and the finished program is in .bmp or paintbrush. then you can edit it if you want. anyone wants to make a town, they supply the map, this way us unblessed-in-art people can have this option. they send it in to shadow/elro/whoever wants to maintain the page. then the cick through map is created. but we dont need to get that detailed, just like the area around castles etc. and show where some smaller villages are at. and if theres multiple people updating the page, theres more chances for it to be updated. ill pst a link later, or e-mail me at r***e@a***l.com to motivate me.