Let me reiterate the point that an online-collaboration fanfilm is a vain, sad effort. Novice filmmaking hasn't evolved to a point where dozens of fans from across the world can work together on a single product. Unless you are needing some speciality like CGI help or a composer, films are best made locally, either by yourself or with a crew of some sort. It's unlikely that you're going to find ten people on this board that live within a few hours of yourself and want to help on the film. What is going to keep people that live a few thousand miles away from agreeing to help and then stop responding to your e-mails?
As for online script collaboration? Here's a scenario; one person will suggest basing it off the book, then three posts will begin to question either the legal issue or the artistic one over originality, another five will begin to sidestep the thread towards a debate over the best book to base it off of, one post will be an attempted witty comment, and the cycle will continue, growing exponentially. What do you have if the thread lasts more than a week?
"1. EXT. SPACE"
I've always wanted to do some sort of science-based fanfilm (for some odd reason), but as a student of film, I know one thing: They're damned hard to make! It costs money, time, and experience points, so-to-speak. I certainly wouldn't have tried and make a special-effects intensive, other-world story for my first film. I definately don't suggest it to anyone who either doesn't study the craft and art or isn't at least semi-professional.
I do know that Wing Commander is losing to a few other "universes" in the Great Fanfilm War. Also, there have been a lot of people making fanfilms who are by no means Hollywood types. There have been a lot of mixed results, but each one of them had a lot of hard work put into them, and all of them added to their respective communities.