This is an interesting idea. Generally, the so-called "good guys" end up victorious when all is said and done, but does it have to be that way? Would you ruin a series if the villains get the prize?
As I'm working through my story line, this is a question that has arisen. My Beta team, a lovely group of young ladies, seem equally divided in their hopes for the inevitable conclusion of my series. If my villain not only survives but gets what he is striving for, where does that leave me? How cliche would it be for the next generation to take up the torch of their parents' fight?
Now since I tend to write by the seat of my pants, and since my characters have a rather annoying tendency to do things that I don't expect them to, I can't comment about the eventual end of my series. I guess I'll just have to wait and see who comes out on top.