My friend Dain informs me of this San Francisco Chronicle article suggesting that George Lucas plans to shoot the fourth Indiana Jones movie in 2007, with a spring/summer 2008 opening.
I'm unsure the working subtitle "The Ravages of Time" isn't meant to be tongue-in-cheek. Check out this picture of Harrison Ford:
He hardly looks any longer like the action hero we remember. Of course, if they could smooth out Patrick Stewart and Ian McKellan's wrinkles for X-Men 3, then who knows where that Pandora's Box will end. What do you think: is it time for Indy to pass on the torch? If so, will this be a "Son of Indy" tale? Should Sean Connery return to represent three generations of archaeologists? When should the story take place — 20 years after the last one?