There are definitely spoilers to follow in this post and the one I wrote last night which appears right after this one, so if you haven't yet seen the finale - Stop Reading Right Now.
Here are some random thoughts with regard to the final episode of the Sopranos
After AJ's SUV blew up and his parents bawled him out for not being more responsible with his very unsafe catalytic converter (still don't understand this one), AJ discussed the incident with his therapist. It was the second time or third in the final episodes that AJ seemed positively delighted watching something violent happen in front his eyes. You may recall how excited he was when AJ participated in the maiming of that poor college kid who owed the two Jasons money for a football bet. And I seem to remember AJ laughing at the same kid coming to school a few days later on crutches. I may be reading into that behavior but it reminds me how often Tony turns to violence to relieve his own feelings of frustration.
After Bobby's funeral, Janice goes to see Junior in the institute where he's wasting away into nothing. She told him that Bobby had died. I thought it was because Bobby was like a son to Junior but it turns out she was just trying to get at Junior's money. Now that Bobby's dead, she needs a new ATM. This thought was confirmed when Janice tells Tony that now she has to find a a new husband. She laughs it off as a joke that only Tony would understand, but Tony knows it's not a joke. When Tony asked Janice about Bobby's kids, she was willing to let Bobby's son go live with an aunt, but wanted to keep Bobby's daughter around because her own daughter was so fond of her "big sister". She's a witch. When Tony realizes that Janice is going to ruin those kids and after Uncle Pat tells him that Janice is trying to get to Junior's money, he went to talk with Uncle Junior to make sure that he left his money to Bobby's kids but it's for naught because Junior has completely lost his mind. He became the crazy man he pretended to be to get out of being prosecuted.
I've read a few recaps and comments that suggest that characters who had died in episodes past were seen throughout all the scenes but I didn't see that. I could be wrong but I feel like a pretty dedicated and knowlegeable fan of The Sopranos.
The Blank Screen
I've also read a lot of theories about the blank screen at the end of the episode.
I agree with anyone who said that Chase left the ending up to the audience but I still believe it to be a big F--- You to his fans.
Even if nothing happened, he should have just ended his story.