So, as we all know at this point, someone is going to die at the end of AvX. It is commonly believed to be Cyclops, however I disagree with that. While it is likely, I think they're making it too likely. As if they're teasing us with it. People think that the Cyclops from the Marvel Now promo image is the 1960's Cyclops, but if that's so why is he wearing a new (horrible) costume while Jean Grey isn't? Plus Bendis said something about Cyclops and Wolverine's reaction to seeing Jean again in an interview, which he very well could have said just to avoid spoiling the finale.
Now, take a look at this image.
The one on the left doesn't really matter for this topic, I'm focusing on the one on the left. Seeing as the only people seen are Avengers, this leads me to believe it's going to be an Avenger. Now, the other popular theory for a death was Iron Man, but he has a movie coming soon and you can see his feet on the cover. In a recent New Avengers arc a connection was built between the Phoenix Force and one of the past Iron Fists. So far that hasn't really moved into the main AvX storyline, but I think it's coming very soon, and I think it will lead to the death of Iron Fist. Fans of Danny Rand know he is a very noble character and if put into the situation, would sacrifice himself to save others. I think that Danny will end up being forced to contain, ward off, or "destroy" the Phoenix Force to save Hope, his friends, or the Earth itself.
This is just my theory, however, and I'd like to hear your own as well as your thoughts on mine.
EDIT: Another solid theory is Namor. Namor has connections to both sides, so his death could be used to hit them both hard, even though anyone's death would probably do that. It's possible that it could be Red Hulk as that is a very big crack in the ground and he could revert back to his human form. Not to mention that he is being replaced with his daughter as the star of his ongoing book. Luke Cage is another possible option, as his death could symbolize the end of Bendis' Avengers era and give reason for the New Avengers to break up, which they supposedly are, but I'm not sure if that's true or not.