If they do kill him off, they can't possibly kill him off the first or second episode into the new season, at least that's what I think. He was shot in the stomach, (not the heart or neck or head) and he looks like he has plenty of cushion for it.
Though Tony dying in the last Sopranos episode ever (a series finale) might be a possibility and that would be a fitting end to the whole show. Again, just what I'd do if I was the creator/writer... But I'm really no Sopranos expert or anything!