Quarto: It helps to have people who're actually involved in the industry - who know exactly what needs to be done. (and have done it before) The thing that I see happening more than any other is that these fan projects bite off more than they can chew.
Let's make a game where you can build your own starfighters! And run around entire planets! Lots of planets! And full-blown asteroid bases! With running gun fights! Etc... Now, unless you're packin some experience with database-driven art creation, and some hefty art/programming skills, that projects gonna fail faster than Ford pinto rear-ended by a Ford Expedition. Boom.
Everyone's got ideas. Some might actually be good ideas. But unless you've got some skill and ability to back them up, likelyhood is that they'll never go anywhere.
The other element is *fun*. I often see various ideas of how to turn WC novels into games. Action Stations and the like. The biggest problem with this, is that these are BOOKS, not GAMES. Books do not require interaction from the reader. you're there along for the ride, and all the fun comes from the ride itself. Games are all about interaction with the player. the fun comes from interacting with the environment. You cannot directly translate anything done in the books to a game without running into major problems of playability and game logic. I just does not work. So - the books can be a basis - but if something in the books isn't fun, or if it causes the player unneccesary grief, then it's gotta go. Whether it's a major feature in the book or not. It's just common sense.
It gets really bad when people offer to help, but present no real skills but the ability to play games. And they want to learn. I really hate to break it to you guys, but taking time out of actually *creating the game* to train you how to do it is a horrendous waste of time. This is why game studios almost never hire fresh-outa-university-artists when they're in the middle of a project. They have to take a productive team member and turn him into a baby-sitter for anywhere up to 6 months. they're paying two people to basically do nothing besides learn how do do what one of them already knew how to do!
Now, I know these various fan mods and games appreciate your enthusiasm - really, they do - but unless you posses already usable skills, they're not going to want your help.
The only exception to this is the Beta/Alpha test stage - then devs need as many warm bodies as they can get. Unfortunately, this stage doesn't come until the end of a given project, and they tend to last for fairly short periods of time.
I've personally been involved with several failed fan projects - and I'm not ashamed to say it. Every single time the failure has stemmed from the lack of either direction or programming support. I've always had plenty of artwork and pretty stuff to make the game visually interesting, but never been able to follow through on a *real game*. I hope to change that.
So in conclusion - If you start a fan project - have more than a good idea. Have art and programming support - and run the idea by quite a few people to make sure it's not just a good idea because of that stale pizza last night.
And good luck to all the existing fan projects! I hope you don't go under.