And in other news, I had another crossover idea...Battlestar Galactica/Firefly.
The premise of Firefly is that humanity is alone in the universe -- there are no spirits/ghosts, magic, aliens, AIs, or anything like that.
While this makes most crossovers a little tricky, its a good fit for BSG, which differs only in the existance of a single race of AI: the Cylon(s).
The only question - as far as I know - is this: which came first?
Option One...Firefly's "Earth that was" is a legend that culminates in BSG's Colonies searching for Earth. Under this, the Alliance would most likely the foundation for the Colonies' very existance.
Option Two...Galactica came first. Regardless of if Galactica ever finds Earth, said planet has by now become irrelevant, both it and the search for it is the legend of "Earth that was." The wandering Colonies grew into the juggernaut that Mal Reynolds knows as the Alliance; no idea what happened to the Cylons.
Option Three...I've no idea. Theories?
this crossover idea hit me when I was listening to the radio, and I heard these lyrics:
Time keeps on slipping, slipping, slipping,
Into the future.