So after a full day to reflect on this thing, I still have the same beliefs about the ending that I did when I initially saw it. I'll preface this by saying that I think the final scene was superb, shot brilliantly and created as much tension and goosebumps as any scene in the series' history.
In my personal opinion, the blackness was the audience getting whacked, as many on these boards have discussed, and was my theory at the time I watched it. I said this in a previous post, but the Sopranos really was the ultimate voyeur experience -- most of us would never want to be a part of that life, see what they see, do what they do, but this gave us all a chance to be a wise-guy for an hour a week, and bear witness to dangerous and extremely disturbing situations from the safety of our living rooms. The scene going black was, to me, the writers saying, "Okay, we've told you more than enough, but while these people have to get on with their lives, you're not allowed to watch anymore." I honestly think this may have been the absolute best way to leave it -- ambiguous, sure, but in a good way.
That said, any opinions anyone else has are perfectly valid, and really none can be definitively proved or disproved. I think the most telling thing for me in re-watching those final minutes was all about Journey. First off, the lyrics in Don't Stop Believing are so fitting -- "Some may win, Some may lose, Some are born to sing the blues, But the movie never ends, It goes on and on and on and on..." Even more interesting to me was the other track on the jukebox that we all got to see -- Any Way You Want It.
And that's the point. Chase knows he has/had a very intelligent and thoughtful audience, one that he's never spoon-fed information to and one that clearly likes that about the show. There are plenty of unanswered questions in the series, many of which simply gave way to more important storylines, just as happens in real life. So, why not end the series on the same note, forcing the audience to think and make conclusions rather than accept an ending that he himself picked?
Honestly, the fact is that David Chase owes us nothing -- he's already given us 86 episodes of arguably the single most brilliant show in the history of television, one that permeates so much through society that nearly every radio and talkshow host talked about it today, even the guys from PTI on SportsCenter. I also agree that no matter what he did, people would've been dissatisfied, because that happens with every huge hyped-up event (anyone remember Scott Stadium in 2001? Haha...).
Anyway, I hope this discussion keeps going, because this series is something that we're all very privileged to have had the chance to watch. Agree or disagree, those are my thoughts. Talk on.