The script idea is fine, except it excludes a great number of people who want to contribute. A lot of fans are unable/unwilling to devote the time and energy to putting together an actual, working script - some may rush to finish, not developing their ideas properly, and others may just give up in frustration. A lot of fans would like to contribute scenarios, ideas, key scenes, dialogue, story arcs spanning a few episodes, etc.. Remember that it takes several people and several months to put together scripts for the show - the writers work off of a framework put forth by the producers, then fill in the details, often on more than one episode at once.
Maybe an open forum for ideas, which are discussed and developed by members, and put through a sort of filter - the moderators? Give this about a two-three week time limit, maybe. The ideas would be collected and further discussed by the moderators, who would act as the producers of the season. Maybe a seperate thread for basic scenarios, one for more detailed ones, something like that.
Maybe individual members could also be asked to develop their own ideas or others' in conjunction with theirs further, into spec scripts (basic outlines), which other members could help dialogue and develop further?
Just some ideas. I honestly don't know anything concrete to suggest to get this baby off the ground. I will tell you this, I am all for it, I am absolutely sure I'm not the only one, and if all of us pull together and pool our resources, I think we can do it.
-DD