2. Otacon will not die.
3. The Boss will be involved somehow, or at least mentioned.
4. The big twist - Snake doesn't die either! And neither does Meryl! Or Raiden! (Vamp does, but he gets better.)
5. Cyborg!Raiden and Vamp break up, but continue to meet on occasion for attractively choreographed homoerotic fight scenes.
6. I would say that Emma comes back as an undead badass, but since we already have Raiden...
7. Raiden dates one of the B&BB girls after she gets over the crazy, but she dumps him because of his incessant Snake fanboying.