I would say Neil and Todd are each others opposites. Neil has lots of self-esteem, good grades and (too say the least) caring parents. Todd suffers from lack of self-esteem; his worst fear is to embarrass himself. He can"t even read something aloud for the class! Todd also suffers from bad relations with his parents (he feels unloved and unwanted, living in the shadows of his successful brother), it's like they don"t even know he exists. (Todd got the same "useless" gift two years in a row, a desk set). .
However, things start to get a bit better when Mr Keating is assigned as the new English teacher. At first Todd hates Keating more than anything; he is forcing Todd do "embarrassing things" like writing poems and reading texts for the class. However, after a few Dead Poets Society meetings, Todd's self-esteem hits the sky. It's like he is a whole new person. .
Things are getting worse for Neil though, it's almost like the two of them switched place. The main reason for this is Neil's father. The relationship between him and Neil is very cold and one-sided. The pressure on Neil from his father is outrageous. Neil has nothing to say about his life, everything is controlled by his father. When Neil's father finds out that Neil secretly signed up for a play, he gets furious. Not only for the fact that Neil signed up for something without telling him, or that acting was considered "low-status" at the time, but also for disobeying his strict order to quit it. As a reaction to this, Neil's father decides to resign him from Wellton and enrol him to military school. At this stage Neil's life tears apart. What Mr Keating said about seizing the day is no longer possible! He refuses to live as a robot! That mixed with his feelings at that time, makes him commit suicide. .
So what will happen to Todd? I think it's very hard to picture yourself in his position. If he doesn"t get expelled for the gesture Todd started when Keating left Wellton (standing up at his desk, soon followed by the rest of the class), I think he will keep on "thinking for himself".