The newspaper helps to demonstrate Keller's detachment and denial of current events, signifying his guilty withdrawal from "the news" and the world.
While Keller has not become a recluse or withdrawn completely from social life, he has chosen a path of denial. He does not read the actual news oriented news sections of the paper. Instead he reads the sections that relate to entertainment.
By the end of the play we can see that Keller pursues a line of moral denial as he persists in defending his decision to sell the faulty airplane parts to the military. Keller's choice not to read the news pages of the newspaper symbolize this denial.