Well, if that is the song it is specifically referencing (and listening to it, that seems very likely), the song is about 2 people who fight over a girl. The singer kills the rival and then goes on the run, fearing death and justice. But he needs to return to the girl Felina, facing certain death. And then he dies with Felina kissing his cheek. So much of this story covers the season so far: Felina (Jesse) flirts with a new man (Hank) and there is a fight. The rival dies and the singer flees. That's where we finished. So based on the song, it sounds like what we all expected: Walt is coming back for Jesse (presumably also taking the time to spy on loved ones so we can see how they moved on through his eyes, the way the singer looks onto his hometown with longing. Of course, maybe he's just checking in on them by using the internet or something. But Walt needs to go back for Jesse and dies, either by the cancer or by whoever he needs to face to save Jesse. Jesse either forgives Walt or shows him sympathy as he dies (or it twists the end of the song by having a "kiss on the cheek" gets replaced with spitting on his face).
Of course, that's all fairly general. Can't wait to see the details! TWO MORE EPISODES! And you know that the cliffhanger next weeks is going to make you even more crazy than the last one!