It was so sad when Todd killed Andrea. I think that was just the nail in the coffin for Jesse. He already had some serious issues with guilt. Then Walt goes and tells him he watched Jane die, and then he has ANOTHER girlfriend die because of him. This is it. There was some chance before that he might have been able to get out, get some therapy and go on to live a "normal" life. No chance now. I'm so sad, Jesse is by far my favorite character.
I don't see the adopting Brock thing happening. Adoption is a ridiculously long and drawn out process and involves all kinds of legal/state checks. Jesse certainly wouldn't make the cut and not to mention you have to go through numerous next of kin before just anyone can adult a child.
That being said, I don't see this ending being one where we get a glimpse into the future at all. I see it being something immediate, story wrapped up, the end. If it turns into a, "Oh look, there's Holly in the grocery store 15 years from now and she has no idea Jesse was just her cashier" kind of crap I'll throw up. I just don't see them doing a future peak.
Meganhaynes, I agree. The only possible way that Jesse could "adopt" Brock would be if he just took him and ran away with him. Jesse wouldn't do that though because he has Brock's best interests at heart and he knows he couldn't provide him with a stable life.
I also don't think we'll get a glimpse at the future, but I would actually really love to see one. Not something as cheesy as Holly unknowingly running into Jesse, but something similar to the flashforwards that they have at the beginning of some of the episodes. I would love to see Skylar helping Walt Jr. move into college, and some kid on his hall comments that he's from "that meth town with that Heisenberg guy." Or the drug cartel talking about the "Heisenberg days."