First of all, a huge thanks to everyone who voted and commented. (I will be making individual responses at some point, but probably not tonight - knowing me, I'll probably get around to them in February *facepalms*). It was very interesting to see what people thought about the issue.
On the one hand, yes, I definitely agree that whatever works for my story is how the book will end. (It's also the reason that, if JKR kills Harry, I won't freak out - if that was the way the story ended for her, that's the way it ended. Her decision). But, at the same time, I don't want to write something that will end in a way that is disappointing, or unenjoyable, or even frustrating for a majority of readers. I've read too many books that left me feeling kind of, "WHY???" at the end, and I'm not sure I want to do that myself.
Still, after I posted the poll, I realized that, in a way, I was asking a stupid question as pertains to this particular novel. There's no chance this will have a "happy" ending - I'm sinking the "Titanic." But, there are different ways I can go as regards the fictional characters I created, as to who lives and who dies, and what sort of shape they're in (emotionally) at the end of all this. I'm still not entirely sure what I'll end up doing, but I will try not to make it so depressing that it ruins the whole book. Although, to be honest? My inclination is to go with pretty darned depressing. There must be some ray of hope though, mustn't there?
Hmnh. I think with that in mind, and knowing what I *have* to do to one of the characters, that probably should help me decide what to do with the other. Heh. Nothing like being cryptic, eh? But surely, no one wants to read spoilers. So, I'll try for "bittersweet" rather than "wants to make you spork out your eyes, like something from Oprah's book club." (Although if I could get my book into her club, let me tell you, I'd be one happy, happy bunny, regardless of how the book ended). :D
I was heartened, however, to see that a majority of you did not require a wholly happy ending. (12 votes for happy versus 14 votes for sad and a bit of both, combined). Because, like I said, I'm sinking the "Titanic." Happy, it ain't.