Okay, from what I've thought of so far, the major items we would need to decide on are these (please add to this list if you can) :
-Pantheon (default, homebrew, or mixture)
-Setting type (points of light or something else)
-Starting city/location (default DMG city, homebrew, or mixture of those)
-Surrounding areas (general info only? Not much specific very far out at the start?)
-Meta rules and such (judges, # of characters, forum thread setup, etc)
The smaller the world area we limit ourselves to at the start, the quicker we can get stuff up and going. Using default stuff (if even possible and if people vote for it) could speed up the process as well.
Some of the ideas I've read in this thread that I liked:
-Starting location on a peninsula near ocean/sea with enough wilderness around to provide starting adventure locations and maybe some varied enviroments. Also some nearby smaller islands.
-Possible access to Astral Sea from ocean travel (similar to how some areas of world naturally link to Feywild or Shadowfell. Maybe some deep caves could connect to elemental chaos as well?)
-Peninsula has natural barrier which kept some devastation from catastrophe at bay. Maybe high mountains with tunnels through that have been taken over by monsters. This could be a neat way for characters to affect the world. If PC's can clear the paths and secure the trade routes, the starting city can reestablish trade with outside world?
P.S.- For anybody reading all the above and thinking 'Gee, he's posting alot about this, maybe he does have the free time to be THE MAN.' Sorry, not really. This is just because it's Friday and work isn't very busy today, so I'm allowed to surf the net or whatever when not working. Most days I'm too busy to post this much.