If you're going to use gamemaker to do this then I can't help with the programming , but I can do sprites/ music (called it first!) and story.
BTW, if you guys are serious about this lets ask Al to help... he could make some code changes to help with the project. I mean, even if we don't get a prize think how much exposure GameMaker would get if we entered!
Also, what kind of game do you have in mind? Game Maker is kind of best suited for RPGs so that might be a good choice...