GL, Spielberg and Ford are still discussing Indy4. Harrison said he will do it only if he really likes the script.
Yes, there were originally nine stories....I don't think GL will get to them. He's getting too old. And look how old Hamill and Fisher will be. And Ford won't touch it. Better be content with six, boys and girls.
EU is all you've got.
Do you really think Harrison Ford would be able to say no? He's not exactly made great films in the past few years. And Star Wars is his kind of movie just like Indy.
If Lucas went to him tommorow and said I'm going to make three more Star Wars films and I want you to be in them, I don't think he could turn him down.