Having read through A Storm of Swords, I was caught off guard just like everyone else until a friend of mine at work mentioned he thought it might actually be who is mentioned in that article and that he has not yet been seen, only mentioned in passing here and there through all five novels. I think its pure awesomeness that Weiss and Benioff did what they did with this character cause now for the first time we know that there is indeed a BIG BAD out there who is on par with Sauron, Emperor Palpatine or Lord Voldemort. I love it and it makes me want to devour A Dance With Dragons and just ups my anticipation of The Winds of Winter even more. And at the end of the day, who do we have to thank but Martin himself for allowing this. Sure, it sucks that HBO dropped the ball with the reveal but this just adds another fantastic layer to what is already a glorious universe of storytelling.