More Sopranos final episode talk: read at your own risk.
A couple of people (probably the same people who see faces in the moon's surface and animals in cloud formations) have opined that David Chase was attempting to tell us that Tony Soprano bought it in the season finale--more specifically, that he was killed by the man who went into the bathroom, or by the two black men who entered the restaurant. The sudden cut to black, they say, was to show that Tony "didn't see it coming," as one character said in reference to a hit.
I wholeheartedly reject that explanation.
The scene was not set up as a POV shot. It was a third person POV shot, showing Tony's face along with the face of his family and the scenes from the inside of the restaurant.
No, what we have here is an episode so wretched that fans are trying to create another explanation. No hit... but one big foul.