TO my knowledge there won't be epi. 7,8, or 9. When GL was writing the total story he thought that it might take 9 movie to complete the story. After a while, he decided that 6 movies would do the trick. I believe I saw a quote of GL somewhere stating, "I have no interest to continue the Star Wars saga after the Battle of Endor." After all, if he did those, he would be around 80 by the time they were finished!
Yes indeed. 12 films and he decided to make only one: ANH. When that was a succes he decided to make three. Only when he saw the technology of Jurassic Park he decided to make the PT. He just sort of makes things up as he goes. So who knows. Maybe after he finishes the PT and waits a few years, he might get another SW itch. Would be too bad by then I think, because the original actors will be too old to play their original parts.