Brad suggested I put this up after we had a conversation along these lines, and many people since have said to me "Well, what did you want?" Now we are not all screenwriters, but it might be interesting to get some notes toward what we all wanted and did not get.
For me, I think a key question all along has been Does Humanity Deserve to Survive. A good portion of the show had been blurring humanity and the cylons by putting them on the same footing (removing resurrection technology, having them fight with each other, ignoring the super-strength, ditching the sleeper agent thing where it seemed like they could be remote controlled -- ultimately the point of finding out someone was a cylon was you were finding out someone was a traitor, but since that was not the case for the final five it again seemed like a bit of a fake out to have them be cylons at all). So the real question was Does Everyone Deserve to Survive? Once you put that question in play for so long, I think you deny the possibility of some wonderfully happy ending, since if they do deserve to survive it is going to be a close call whether the should have (or why ask the question?). So for me I needed to see a significant number of folks just not make it -- the finale could not even give Helo a heroic death-- and those that did should not be walking though a green and pleasant land. They should be ok, but it should feel like life, not heaven. In fact I think I really could have gone for an ending in which someone made the call to just push everyone into the black hole, because the universe would be better without them, and maybe Hera escapes somehow, the last potential of two doomed civilizations. Maybe like some combination of Batman's resurrection in Final Crisis and Superman's story her little rocket lands on a caveman planet, guided by some less heavy handed version of the device that got everyone to Earth -- except now that I write that it makes no sense, because that radioactive planet needs to be the real Earth and not a fake-out. Brad said that he would have wanted the final five to suddenly "switch on" and do something monstrous, activate the cylon "plan" we have been hearing about in the intro to every episode since season one, and which seemed to have been just dropped. Maybe there was some reason why they needed to wait so long, and even have people accept them as Cylons (and let other cylons on board and paint the ship with cylon goo) before the last phase would begin.
I do not exactly have it worked out. One of the reasons it is so hard to think of a proper ending is that the writers really write themselves into a corner, which is why the God stuff came so heavy at the end -- it is the only way out of the box they were in. I have no idea what to do with Kara. She can't be like the Six that only Baltar can see -- Kara was different because she found her body and questioned what she was. But then I can't think of what she COULD be given how the show handled her. Some people suggested that she was a hybrid, the child of the never seen Daniel Cylon and someone, but I am not sure how that would work out.
Here is how the show should have ended: it should have been cancelled after season three so we could all complain that it was one of the great shows that died before it could have reached what surely would have been an amazing conclusion, like Firefly.