A report from To Be Continued IV in Chicago were GRRM is the Guest of Honour has been added to the So Spake Martin section, and more will likely follow in a day or two.
According to GRRM he has about 100 manuscript pages left to write of AFfC, and he expects that the publishers will rush the book out as quickly as possible once its all handed in. He also noted that he has some chapters done of the next book, and half of the next Dunk & Egg story.