Now that I think about it, it would be great if IW kept bringing him back from the dead in every game in the series but would never explain why or how and only leave hints.
Like in MW1 he got shot in the face so he wears a mask in MW2 where he gets burnt alive so he wears like skin tight armor or something in MW3 where at the end he gets his hand chopped off so he has an artifical hand in MW4 and just keep adding to it.
I would honestly love that. Even if it is jumping the shark.