For what it's worth, my take:
Phil, I think, played made a "lose" move by taking out the cappo, and he all but knows it. The game really had passed him by, and then, in one last gasp of the mutant rage that is beneath all of them, he makes one last futile move. but, no one in his gang will feel safe; he will go, and I am betting that the son of the former boss emerges.
Tony somehow survives but Jr and Paulie and Sal are all gone, as is "this thing" of theirs, at least as it once was. Now, Tony is surrounded by the likes of Bobbie and Chris, and the kid in New York, who no more resemble the old "thing" then Chris's movie does the Godfather. In the end, all that stands is a bunch of guys who kill, not just because its only business, but also because they are animals. What we liked about Tony and the boys can no longer save the venality that is the mob.