So this is the bottom line - George R. R. Martin created a compelling narrative in an expansive, extremely textured world and it was wonderful. Then, like most successful writers (especially those who shoot for epic sagas), his editors became afraid to tell him to cut anything at all ever and the saga got weighed down with unqualified bloat. Personally, I refer to this as Robert Jordan Disease and the only tried and true solution is the death of the author. Book 4, upon which the next season is ostensibly based, it an awful, awful piece of shit. It took G.R.R.M. five years to write it, and he has admitted that it was really hard for him to complete. This should be setting off warning bells in any real fan (the 5th book was better, but not by much). Book 4 advances none of the major storylines in any real way while getting bogged down exploring stupid little narrative tributaries that no one could possibly give a fuck about unless they are idiots. Approximately 25% of the book is devoted to describing the sigils of minor Houses and going into excruciating detail about what kinds of food people are eating. Not even joking here, if an editor had the balls to tell Martin to cut down the descriptions of food and house colors, Book 4 would be 200 pages shorter.
The moment where the propulsive momentum of the show crashed headlong into the squalid flaccidity of the novels was inevitable. I am skeptical that Martin will ever finish this book series, which would suck and I hope if that happens he gets stabbed to death by peasants with pitchforks. But, it is well known that he has given the show runners the story's broad strokes and I hope that they take that outline and run with it. So that is what we are seeing, I think. They are positioning themselves to run with the show in new and interesting directions because we have now reached the point where the books start to really suck. And, personally, I am excited for that because this show is awesome and the choices they have made have been very shrewd.