i don't think there will be any new films, honestly.
if they do, they will have to just adapt a comic book instead of coming up with a new mcguffin.
however, the comic books all feature a younger indy.
there would have to either be a sequel to the comic book (return to the sargasso, or something) or they would have to replace harrison.
neither is a good idea.
this should be the last indy movie.