I am loving this show. Jimmy is such a good character, but in the end I think we will see something really bad happen to him, maybe some kind of betrayal, that will ultimately steer him to become Saul.
Right now, I'm thinking this betrayal will come from his brother, who after working on the case has found that he doesn't have a disability after all. The first scene of the show showed Jimmy giving him the letter about passing the bar, of which his brother was not that proud. To be honest, I think Jimmy's brother was probably a real big a$$hole before Jimmy started to take care of him. Because Jimmy took care of him, I think he expects him to respect him more, but for the duration of this season, the word 'respect' has never come to my mind when thinking of their relationship. In the end, his brother will take the case back to his firm and cut out Jimmy, leaving him devastated and determined to go about things like he used to as Saul Goodman.