I just read the novella "I Am Legend". The title makes a lot more sense for *that* story than for the movie. I'm not quite clear why they bothered hanging the title on the new movie - the movie's story had more in common with 28 Days Later and other modern-day zombie flicks than Matheson's story. I suppose there's the bacteriological explanation of the scourge, the madness of the characters, their inclination towards mad science, and their essential isolation. In the end, the novella is an ironic late-modern version of Lovecraft's "the Outsider", about the loneliness of becoming the monster. The Neville of the movie never explicitly becomes the scourge and monster that the Neville of the novella has already become on the first page. His monstrousness is less explicit, less textual, left to interpretation, and subverted by Smith's essential decency as a film presence.