Harrison Ford recently said in an interview that he thought wasn't sure if there would be another Indiana Jones movie, but looking at recent photos, it is hard to imagine him suiting up for the role again.
At 69, you can't blame him for having thinning hair, but unless he plans to keep his fedora on throughout the film, he doesn't quite look the part anymore.
But there are ways he could try and regain some of his former looks. A regimen of FDA-approved Propecia or Rogaine would help prevent hair loss, while low level laser therapy would help stimulate healthy hair growth.