It’s looking more and more like a fifth “Indiana Jones” installment will happen.
There is a glimmer of hope, though. According to new details released in Stuff Magazine, the fifth installment would be the final one for the famous archeologist.
According to reports, Harrison Ford has agreed to come back as the archaeologist and adventurer one more time, and will be given an “emotional and exciting” sendoff: “Harrison is on stand-by for filming next year. This looks like … an emotional and exciting conclusion to the franchise, with Indy facing his biggest challenge yet.”
The plotline of the movie would center on the Bermuda Triangle.
“George [Lucas] and Steven [Spielberg] have been working on a script and it’s almost there,” the source said.
Shia LaBeouf, who played Indiana’s son Mutt Williams, will also appear in the new installment.
“Shia LaBeouf has a central role again as Indy’s son, but this will be a blockbuster made in the old-fashioned way rather than the CGI efforts of the last movie,” according the source.

Lucasfilm just recently debunked this one.
http://www.slashfilm.com/2010/06/08/rumor-indiana-jones-and-the-bermuda-triangle/
I think that the mystery of a great character will be lost- if Indy 5 is anything like the last one. I am of the persuassion of stop while you can. Don’t let there an elvis bloated period to poke sticks at with. That’s my reaction.
Admittedly, upon hearing news of a 4th installment years ago and checking obsessively at theraider.net for info like a madman last year- I, like man, bought in to the hype. I was let down.
Even now as an obsessive fan I believe if the script was handled differently to Crystall Skull – It may work. But I’m very much of the paranoid persuassion that this so-called emotional ending will suffer of Crystallskullitis. I really do.
Having harrison ford return as an older character would not have been a bad thing. I think that some of the situations and characters/development in Crystall Skull cheated original viewers of the series. I think that the 4th leaves an unfortunate blotch on any future DVD packages.
The first three “Indys” classic, “Indy 4” a total disaster. Lucas and Spielberg, usually so savvy on plot and audience expectations, threw in everything but the kitchen sink seemingly in order to please. Dong so crossed the fine line of suspension of disbelief they so expertly walked in the early films. Indy 4 had too much CGI, beginning with the warehouse scene, continuing throughout to the giant ants and culminating in the totally over the top final UFO liftoff. Scenes with Marion, so charmingly written in Raiders, came of as a long marriage on the verge of collapse. She was just too “bitchy”. No really threatening “Naziesque” bad guys hurt the plot greatly. Of course, Harrison still can pull of the character and still looks fine in the costume but the surrounding cast was totally unnecessary, a shock when you have the incredibly talented Kate Blanchette, what a waste. And, what was that far-too-bright final wedding scene that looked all too tacked on? I suppose we can’t have a bastard Mutt, the bible-beaters wouldn’t approve. I was hoping there would be an interruption and Indy get suddenly recruited for some new adventure. Also, if there had been on more close up of the “crystal skull”, I would have thrown up. Someone must have really liked the work props did on that piece. Indy 5, stay away from the Bermuda Triangle! More CGI coming on that one you can be sure. I’d love to see Indy continue as long as Harrison can lift the whip but let him get back to jungles, deserts, the great sites of the world in search of boarder-line believable objects like Noah’s Arc, the Lock Ness Monster, Big Foot, hidden pirate treasure, etc. There’s so much out there with which to play