Jo tells us today on her website that she is hard at work writing Book 7, but that she is "alternately elated and overwrought" to be writing scenes she planned as much as 12 years ago.
I know as a reader I have mixed feelings too. Reading the last book will be wonderful, but also like forcing yourself to say goodbye to friends and a world you know you won't see again. Jo has been firm that the series ends with this one with the possible exception of an encyclopedia of her wizarding world for charity.
Jo also wrote about a dream she had that may or may not give clues to how one hunts for Horcruxes.
In her "Rumours" section, Jo squashed another theory, but it wasn't one that had big play on the forums. It was a theory that was probably based on the alchemical interpretations of the stories because it proposed that Harry and Voldemort would combine into one being.