For an author that is done signing books in quantity, he certainly has signed a lot of books in the recent past. If you look at the bottom of this page (
link), you could probably argue that he's slowing down, but as long as he's writing books, he's going to be signing them too: trade and limited editions. Not to be morbid (hey, I read a lot of Stephen King growing up), but I personally think that it's more likely he stops signing books because he dies or suddenly retires than it is that he keeps writing and concurrently stops signing books.