1. I like the name "DarkWORLDS" better than "DarkTOPIA" but that's just me. (and I like "DarkLINK"). Another name that came to me was "Where?" You know, like "There" but more of an Abbot and Costello routine waiting to happen...
2. I like the Times Square billboard idea where there can be major announcements and/or rented space to advertise personal projects. I also liked the renting personalized rooms for a short time and would like to build upon that to include people paying money (real life money) to own a "house" or something big, along with other privilages (like truely unique avatars maybe?). That should help raise money for server space/bandwidth.
3. A nice assortment of built in available avatars/customizations. I am a fairly decent programmer most of the time, but my 3d modelling skills are subpar
4. I don't know about this one but maybe file transfer like in irc? Easy source code exchanging? Potential security risk? Not necessary? I don't know, it just one of the features I like in irc
5. I like the half-life tram idea as well as the teleporter idea and maybe a hoverboard or something (really depends on the size of this world...as said before, if it's too big then finding people becomes a problem)
6. Not really sure about this one either but maybe an http://www.isketch.net type of place? Fun little multiplayer distraction like the trivia room.
7. Just like in the japanese sky city there can be a stadium where we can all play BLITZBALL!!!!!!!!!! (totally kidding...don't hurt me)
8. How will we earn the credits for renting/buying stuff? Trivia, constant increase over time (unless altered by admin), I dunno...racing?
I'm trying very hard not to suggest anything too mmorpg-like cuz I know that's not the direction you want to go in. Anyway, this is just a few random ramblings...make of them what you will as it 3:48 a.m. and I must retire for the...um...evening?
RMPVG (Real Men Play Video Games)