I have done some searching on the web, and aside from some minor fan fiction, and by minor I mean 20 pages or less, I really have not seen anything in the way of geneforge side-stories or spinoffs. Personally I think that the series would make an excellent source of literature, if Jeff ever thought about it, (which he probably has, he's a bright guy) and you have several decades of stroyline during the rebellion, or the centuries preceeding it, to work with.
I do a lot of reading in the genre, and by a lot, I mean about 3-5 300-500 page novels per week. I also write, although I never intend to get published,)I currently have about 100 pages of a novel online), and I would like your opinions on theoretical storylines. I do have some ideas, but i would like to hear some input from the forum first.
Please keep in mind that anything I write would be completely unofficial and nobody would ever make a cent off it. For a sample of my writing, visit the following link, http://www.webook.com/project/Apocalypse-2 Keep in mind that this is my rough draft, most of the typos have not been fixed, and it is merely a prolouge for the novel I am writing. Also, please read the disclaimer before reading.