UPDATED: G.R.R. Martin denies rumor he already finished the books but made deal with showrunners not to publish until end of show

[S.Peelman]

Hiku said:

S.Peelman said:
If this is true they would’ve still had material to go on. Unless the unpublished books are as illogical as the last few episodes of the series has sadly become.

A fair point, but the showriters said that they had known about a very important plot point that occurred in Episode 3, for the past 3 years now.
That means Dan & David had decided on the ending, or at least parts of the ending, 3 years ago. Now this may very well be based on what GRRM told them would happen in the books, and on what he had written at the time.

In the 3 years that have passed since then, it's not impossible to imagine that he managed to finish the books. And that the show writers had already decided on the course their story would take, regardless of what GRRM wrote during that time.

As writers, you want to show that you're capable of writing your own story as well, and not just adapt someone else's work. But they probably did not anticipate just how negatively some of their own later storylines would be received. 

Though I don't think we'll ever know the truth about this, unless Goerge states it officially, or the two books are released swiftly after the show ends.
I'm also hearing now that HBO supposedly wanted to give them the budget to make more episodes, which makes sense because Game of Thrones is a big cash cow for them. But Dan & David apparently just wanted to wrap things up in a few episodes.

With some more episodes, or an extra season, the whole Daenerys debacle that occurred could have been developed much better, and made sense. Among other things.

Keep in mind, one of these writers are responsible for X-Men Origins: Wolverine. And they're now moving on to work on Star Wars...

I agree. I guess there could be more of the books completed now than two or three years ago. I wrote my post before seeing yesterday’s/today’s episode, which I have now seen and thought was actually a step up again. I’d expect the main thing that happens in this episode to also happen in the upcoming books, I do believe GRRM had already layed out plot points that huge.

And indeed, this season, and probably the previous as well should’ve been a full 10 episodes.