I’m a big fan of Heston’s dystopian films as well (and others from the era such as The Andromeda Strain and Silent Running). Will Smith is great in I Am Legend, but I like The Omega Man, which is based on the same novel, better. I assume that Heston must have bought into the Ehrlichian hysteria of the period to have appeared in so many such films in a short period.
I would expect the genre to revive in the coming years with so many storm clouds (peak oil, global warming, war, terrorism, etc.) on the horizon. James Howard Kunstler’s post-peak oil novel World Made By Hand, would make a great film and would be a huge hit if it premiered as President McCain (thank you Steve Sailer!) nuked Iran and sent gas prices above ten dollars a gallon.