The three giants of the golden age of science fiction are now gone. Arthur C. Clarke has followed Robert Heinlein and Isaac Asimov into that unknown territory that all humans eventually travel to but nobody reports back from:
Mr. Clarke played down his success in foretelling a globe-spanning network of communications satellites. “No one can predict the future,” he always maintained. But as a science fiction writer he couldn't resist drawing up timelines for what he called “possible futures.”
Science fiction writers tend to be judged by how accurate their predictions of the future are, and Clarke was better at it than most. But the really great ones -- starting with Mary Shelley and her "Frankenstein," the first novel that could be called science fiction -- use their speculations to comment on the current human condition.
I never got into the "2001" phenomenon all that much, but Clarke's "Childhood's End" was one of the SF novels that first had a profound effect on me. It was written during the height of the Cold War, and its exploration of the individual vs. the group resonates today and will be important for generations to come. There will always be Overlords, and they will too often seem benign.