Last night I started reading I am Legend (after finishing the book I was reading, Wonderland Avenue, a fantastic read, more of that later). It's certainly a lot more involved (naturally, it's an entirely different medium) than the recent movie of the same name and this version of Robert Neville seems to be much, much darker. I'm looking forward to seeing what happens to this Robert Neville and his battle with the vampires.
I have yet to discover from the book how the entire population came to be vampires but I must admit my first thought is that it is not 'as realistic' as the Dark Seekers in the movie; not that any Zombie/Ghoul/Vampire myth is actually realistic.
Will keep you updated on what I think about the book as I progress. Only up to about chapter four by now.