Neville will play a role in defeating Voldemort. I have a feeling that we are going to see more and more of Neville. Harry is the only one of the kids at Hogwarts to know that Voldemort had a choice between Harry and Neville. I would not be surprised if Harry starts to lean on Neville a bit more. First, Neville demonstrated that he was capable of using magic correctly and his bravery. Second, Neville has more potential then everyone knows. Neville has been held back by the memory of his parents and his Grandmothers chiding that he is not as good a wizard as his father.

Harry should recognize that he has more in common with Neville then he does with any of his other friends. Neville was essentially orphaned. Neville was not given a great deal of encouragement by the people who raised him. (Although I think Neville was loved, he was not encouraged). Neville could have been Harry had Voldemort choosen differently.