Wow I haven't been here in a long time. Anyway that's not actually Harrison Ford, it's a wax dummy....lol
And as for him being too old to do the stunts I say you're never too old to do anything.
But you also have to realize that most of the stunts done in the other Indy films weren't actually Harrison anyway, they were his stunt double. I'm sure they'll probably have to use his stunt double a bit more, unless, knowing Lucas, they go the CGI route. Which I hope to god they don't go that way.