April's Vanity Fair does a snazzy preview of the upcoming fourth season of "Game of Thrones" and the topic of the show's life expectancy came up and that the show will soon outpace George R.R. Martin's book series.
Co-creator David Benioff says: "Last year we went out to Santa Fe for a week to sit down with him [Martin] and just talk through where things are going, because we don’t know if we are going to catch up and where exactly that would be. If you know the ending, then you can lay the groundwork for it. And so we want to know how everything ends. We want to be able to set things up. So we just sat down with him and literally went through every character."
Martin adds: "I can give them the broad strokes of what I intend to write, but the details aren’t there yet. I'm hopeful that I can not let them catch up with me."
Benioff and co-creator D. B. Weiss say they would like to wrap the show after seven or eight seasons: "It doesn't just keep on going because it can. I think the desire to milk more out of it is what would eventually kill it, if we gave in to that."
Source: Vanity Fair