To be completely honest, I didn't expect to see much difference between a Charlton Heston helmed Omega Man and the Will Smith fronted I Am Legend, and what do you know there wasn't. Same source material, similar outcome. Other than Legend's CGI that is. As Hello Siesta mentions, the film's defining attribute (throughout its many incarnations), is its religiosity, which skulks in the shadows throughout. Similarly, and likewise differently, Omega Man first smacks religious when Heston meets the other survivors but Legend holds out until the very end to trumpet the Smith character's Christ-like underpinnings and eventual sacrifice. One difference.
Contrarily, Heston's "Neville" ventures into this territory when he finds there are other survivors, or more precisely, when the survivors find him — Smith's "Neville" is somewhat noncommittal about his divinity; one moment waxing poetic about Bob Marley style peace & unity, the next screaming there's no God!. I'm not saying it's what I enjoyed about the two films, in fact I barely enjoyed both (first half of I Am Legend aside), it simply strikes me as lack of effort in capitalizing on Smith's Chuck Noland-esque execution, ... or maybe it's due to the story's supposed unfilmability.
