So on a serious note, does anyone have any theories for the finale? Remember that we know two things for sure: Walt bought a huge machine gun and he went back to his house to get the ricin. The question, then, is who are they meant for?
I'm guessing the machine gun is meant for the neo-nazis (will be pretty surprised if it's anyone else) and the ricin is for his old Grey Matter colleagues.
It's a pretty common guess that Walt will die by the end of the series, but someone made a compelling argument about how killing Walt in a blaze of glory is letting him get off too easy. What if, and this might be a stretch, but what if his impending war against his enemies gets everyone ELSE killed except for him? That would be his punishment, to live the last few months of his life knowing that his family has paid the ultimate price, that everything he did was for nothing, and that it is all his fault. It would definitely be darker than just killing Walt, but we'll see.
As for my personal theory, I don't think Jesse will murder Walt. Jesse is the closest thing to a good person left on this show unless you count Walt Jr. He has done terrible things, but I don't think he's a killer. Before you go and bring up Gale, what I mean when I say he isn't a killer is that there are two kinds of people: those who are okay with taking a life and those who aren't. Walt is most definitely the former but Jesse is the latter. He isn't okay with killing people, but in Gale's case he felt he had no choice and that he had to do it to save the life of someone he thought was his friend. Unless Walt tries to kill him directly in the finale, he most definitely has a choice on whether or not to pull the trigger, and if he does then that will be the point of no return for him. He will have taken a life just for the sake of revenge, and thus he will have become what he despises. Remember that if all he wanted to do was kill Walt then he probably could have done that easily. Instead he teamed up with Hank to bring him down legally.
As for Todd, if Walt doesn't kill him then I think it's within reason to think Jesse could do it. It's not quite the same situation, as Todd and his people are directly threatening not only his life, but the life of someone he cares about. Unless Walt snaps and tries to gun Jesse down personally, he is powerless to threaten him in any other way.
I don't think it's impossible for them to cooperate one last time to take out a mutual enemy, though. As much as Walt and Jesse hate each other now, they probably hate Jack's gang much, much more after the things they've done.
