: None of that is really the driving thing either, at least to me. They had a
: story about her dying. They had her acknowledge and accept that it was
: happening, that her life was ending. They showed her die in as clear a way
: as they could-- she deteriorated and the machinery she was in was
: destroyed. This all had an emotional weight to it. Having a way out of the
: situation, even a believable one, doesn't change the fact that we the
: audience saw her die, and that was the intended take-away, and there were
: no caveats or exceptions or ways out presented. To undo that would render
: that story moot. True, that wouldn't make it a worse story in and of
: itself, and it wouldn't necessarily mean the Chief can't change and grow
: because that happened, but it would take away a lot of the weight of
: context, and it would make it feel less purposeful, and it would set a bad
: precedent.

"Most of me is down there. I only held enough back to get you off the ship."

To me there's plenty of room for her to exist in some form, and/or be rescued in some manner. It even smacks of someone making the effort to give their life for someone else, going through the whole goodbye speech in a noble action, only to be rescued at the last possible second from absolute death. Is that a cheap way out? Many stories do that, because the point of the story isn't "kill with a self-sacrificer" so much as it is demonstrating love that would give its own life, and love that would go to the end of the earth to save a life, ultimately giving a happy ending. There are many styles of stories that use this progression. Halo could go a few ways. But my weight is going on Cortana NOT being lost forever; again, precisely because the two primary characters are a duo and their relationship has been the core of Halo, along with the exploration of the concept of the Smart AI, in contrast with human life.

Your objective factual statements that there is no way it could possibly be true is quite subjective :P
What I see are many plot mechanics and openings for Cortana to continue to exist or be returned to 'life' in some manner. Just because there was an emotional farewell doesn't mean it is and must be the end. I see it like the bad guy 'presuming' the good guy was dead even though he never verified the body; and didn't even think of doing it. Cheesy out? Sure. But I definitely do not see a definitive "Cortana is dead forever" in the plot that we have currently been left with. Far too many other Halo-universe elements are in line to make that turn around.

We'll see, once 343 creates the games and material they've been planning the last few years. :)

I suppose unlike some people, if Cortana is recover in any way, I won't be crying absolute foul on 343 for their storytelling tactics, and I'll likely greatly enjoy the story :)