I don't believe that Tony will die because I think David Chase will want to visit him again sometime in the future. He has too much stature to kill off just yet. Chase is too canny to make the mistake made by, say, John Updike: Having failed to channel a young would-be terrorist very convincingly, Updike is probably pacing his room at this very moment and moaning, "Why why why did I have to kill Rabbit?" ...
Tony will lose the foundation of his life. He will lose at least one member of his immediate family, although which one is difficult to guess. Anthony Jr. has become paralyzed by self-doubt and conscience, so he is already effectively out of the picture. That leaves Meadow and Carmela. I'm guessing Meadow because it would be harder to live with her death than Carmela's â€” and of course it would mean the end of his marriage in any case.
I, too, have come around to the view that Tony won't die - not because I think Chase wants to revisit him, but because I think the show is about the hell that wicked people make for themselves here on Earth, and killing Tony, in a way, feels like letting him off too easily. The Sopranos happily kills off its quasi-innocents (Adriana, Bobby Bacala), its unreflective sociopaths (Richie Aprile, Ralphie, and now Sil), its screwups (Vito, Christopher) and its rats (Big Pussy and a host of others), but Tony and Carmela are the only characters smart enough to understand on some level that they've damned themselves, and I think Chase will leave them alive with that knowledge. (Unless he wants to end it with Tony headed for the light - or the Finnerty family reunion - and finding his mother waiting for him.)
And I'm with Jeffrey Goldberg: Killing Meadow off is way too much of a Godfather III rip-off, and killing A.J. off just feels like a waste of time at this point. So I'm going to join Goldberg in suggesting that the finale will end with the Soprano nuclear family still intact and even with Tony back on top, in some limited sense at least; if any mob boss gets capped in the final hour, I'm betting that it will be Phil Leotardo. The show isn't about the life and death of Tony Soprano, in the end; it's about his soul, and the audience's (increasingly-vain) hope that a criminal they liked might be able to escape his pathologies and find redemption. The end of Tony's therapy, which closed off this possibility once and for all - with Melfi closing the door on him, in a scene that echoed the closing door at the end of the original Godfather - is the only ending that story needs. Killing him would be superfluous.