: That's not really the operative thing any more. It's not a question of
: killing her but of bringing her back. Killing Cortana is something I'm not
: crazy about but can get behind. Doing some (likely quite literal) deus ex
: machina shenanigans to have her stop being dead , that I'm even more
: against than killing her in the first place.

I don't think that'll happen... my theory of her continued existence is entirely related on the digital nature of the AI, and that we really don't know fully what she did or how much of her is implied to be no longer existent. Perhaps even knowingly to her. eg if she had copied herself and the they don't have knowledge of each other (not that that's what could be, just an example). There are a number of plot mechanics that could still have her be alive, without being some kind of retcon or tricky wording or change or direction or whatever. Really, I feel confident that 343 already knows the fate Cortana, so the whole end of Halo 4 would have been done that way intentionally - whether she still exists or not.
But I can't imagine that 343 would get rid of Cortana from Halo in her entirety. Not gonna happen. *knock on wood*