One thing I found interesting that she didn't mention was GRRM's response to a question about how he keeps all the details straight as he writes more books.
GRRM responded that this was one of the things that was making Dance take so long, namely having to go back and check a bunch of details. He said that without search functions in documents he would have gone mad.
He gave a very funny rant about eye color - about how in the real world, we really notice anyone's eye color unless we're very close to them, but in books, everyone has their eye color described. Having to go back and check the eye color he gave for hundreds of characters was an example of a detail that could drive him batty; GRRM said he regretted mentioning the eye color of any of his characters. He also noted that as a brown-eyed person, he finds it annoying that brown-eyed characters are always portrayed as ordinary, while the doers of great deeds always have blue or hazel eyes or something - he notes that he himself was somewhat guilty of this with the violet eyes of Dany or the red eyes of Melisandre.
He said that in all seriousness, what was most important in rereading prior books to make sure he got the continuity right was speech patterns - each of his hundreds of characters has a distinct way of talking that he wants to make sure he is faithful to.
Another interesting thing he mentioned: he mentioned the coming of age of Arya in Braavos in the context of how a writer had to discipline himself to write only as many chapters as were necessary to serve the story, saying that what Arya was dealing with in Braavos could make a worthy young adult novel in its own right.
Another tidbit I liked (this I think from Friday night): that while Tyrion was his favorite character and the most like himself, and for those reasons perhaps the easiest for him to write, these chapters have been harder in Dance because of the dark turn Tyrion's story has taken.
He talked about how in typical fantasy, a magician will throw lightning bolts and kill thousands of men, but in 'real' medieval times, more men died of disease than on the battlefield, due to the unsanitary conditions involved in keeping together a large army - to me, there was a hint that we may see some of this effect of disease in Dance.
In talking about his progress writing Dance, he mentioned that he is now writing the epilogue - this doesn't mean that he's finishing up; he was clear that he was writing this part out of order. As we've heard before, the he said that resolution of the Meereenese knot was the major thing left to complete in Dance.
In response to a question about whether it was hard to kill a character, he said that it always was, even if the character was an evil bastard. He said that the Red Wedding was the hardest thing he's ever written, and that he put off doing it until the rest of the book was complete.
The Friday night reading was the lengthy Jon Snow chapter that others have probably read before, but which I had disciplined myself not to view online. Martin does the voices of his characters very well - I liked Sam's squeaky, stuttering falsetto.
Finally, to me the most interesting thing he said publicly all weekend were some comments about the nature of writing and what he tries to do. He said that pure good-and-evil fantasy wasn't interesting to him; while Tolkien had done Sauron masterfully, he'd had a lot of bad imitators doing 'dark lord' villains. He noted that to him the most interesting characters in Lord of the Rings were the more flawed heroes, folks like Boromir and Denethor.
He made the point rather dramatically by saying that all fiction could be lumped into two types: Good guy punches bad guy in the nose, or the human heart struggles against itself. He said he was really only interested in writing the second kind of fiction.