Bold prediction: Walt's killing Mike either at the end of the season or sometime early in the next one. Mike has too many loose ends and Walt has outsmarted him several times since season 3. You don't think Heisenberg hasn't forgotten about the man who beat the crap out of him (not named Jesse Pinkman) just a few months ago?
Prediction for the series: Walt's greatest enemy in the end is going to be...(wait for it) JESSE PINKMAN. Walt has too many secrets hidden from Jesse, and it wouldn't make sense for those secrets to be hidden forever. If it doesn't come out, then there was hardly a point to Jane's character other than causing those planes to crash into each other (which didn't really alter the show much). There was always a point to the other side characters like Ted and Walt's former business partners who sold him out. There has to be a better long-term point to Jane.
That, and Jesse knows what Walt has done throughout the series, down to last chip of blue glass that was made by the two of them. If the secrets are revealed, Jesse has a ton on Walt, and he's threatened to rat him out before (when Hank beat Jesse up). Jesse is the ideal candidate to take down Heisenberg.
How can you say there was no point to Jane? Jesse was in love with her.
I agree that Walt and Jesse will end up being enemies and that Jesse will find out Walt's secrets. But the question is how? Maybe Saul ends up telling Jesse that Walt poisoned the kid? But Saul would have to be under some serious heat to give up that information, he's proved to be pretty loyal. Can't wait to see how the writers work that in.
Thing is that was in the short term. I'm talking about the fact that Jane really hasn't made a long-term effect on the show just yet. There hasn't been anything about her death that has gone on to effect the show now. Jesse's changes in personality were more due to him killing Gale and working with Gus. Jane really hasn't affected his character in the long-term, BUT, that can change if it is revealed that Walt let her die.
What I'm saying is, things that happened in the past that seemed unrelated to the show in the long term have ALWAYS come back to affect what happened in the long-term. Like Skyler's relationship with Ted. What seemed like just a vengeful affair by Skyler to get back at Walt for hiding everything that wouldn't really be brought up again turned out to be another useful way to deflect the Whites from having to confess Walts' business in the meth business (like when they said Walt was addicted to gambling).
Other examples:
-When Combo was shot down by a kid, the show didn't really touch on it UNTIL it was revealed that the kid who shot him was the little brother of Jesse's new flame. And we all know what happened after that.
-In the short term, I figured Hector Salamanca was going to be someone who would always try to kill Walt out of pure revenge, but it turned out the long-term point of his character was to kamikaze Gus via Walt's planning.
The reason why this applies to Jane is because her death could potentially play a role in Jesse's turning on Walt because it's one of two big secrets that Walt is hiding from Jesse besides him poisoning Brock. Or perhaps, Walt might use her death to continue to get Jesse on his side. He could tell jesse that he always knew what was best for Jesse by using Jane's death. He could tell him he went to Jesse's place that night to talk some sense into him and instantaneously saw Jane choking on her vomit when he got in and thought about saving her but decided it was better for Jesse that she die because Jesse did point out that they would have been dead in a few weeks had she still been alive.
Anyway, I think that would give Jane a point in the long-term rather than just being a girl that Jesse falls for in a season.
