He was never a great writer. None of his books may stand the test of time. A hundred years from now, it's possible that The Executioner's Song still will be read, the way people read The Jungle or Babbitt, not because it's great art but because it's accessible sociology about the era. Hell, Mikal Gilmore's Shot in the Heart one-upped the original, and "The White Negro" feels dated in ways The Electric Kool-Aid Acid Test probably never will.
This isn't the passing of a great writer as much as an occasion for the mourning of a kind of public intellectual that literally no longer exists. If you've ever seen clips of Mailer chopping it up with Gore Vidal, years before any of us were born, you get kind of a nostalgia for a time when men of letters strode the culture with outsized personalities and egos. They were celebrities. They set the terms of debate. They took their roles as public intellectuals seriously, and enjoyed the fame. They used it responsibly. I've never loved his writing, true -- Vidal, Wolfe and Joan Didion played the same game and eventually one-upped him. (Mailer stayed a step ahead of George Plimpton, but "The Paris Review" will outlast them both.) Mailer veered into irrelevance long before Harlot's Ghost.
Still, he strode bigger and grander than any of the young writers we're stuck with today. Norman Mailer crapped bigger than Jonathan Franzen well into old age, and from his grave, he always will.