Everyone hated the last Indiana Jones so the only rational thing to do is make another one. You know, as like an apology and stuff. The Kiwi (New Zealand) side of Stuff Magazine has the scoop on the Indy 5 plot details that you hoped would never surface: 

The new film will be Ford's last, and a return to the series' roots (meaning less state of the art visual effects) after the last entry failed to resonate with fans. (According to a mysterious source) Indy's going to The Bermuda Triangle: "Indiana Jones 5 will begin shooting next year, and much of the plot line will be centered around the Bermuda Triangle, an area over the North Atlantic Ocean where a number of aircraft are said to have disappeared (and definitely not because of f*cking aliens)."

Stuff goes on to add that, according to their (soooo mysterious) source, "George (Lucas) and Steven (Spielberg) have been working on a script and it's almost there." They also report that "Harrison is on stand-by for filming next year. This looks like being an emotional and exciting conclusion to the franchise, with Indy facing his biggest challenge yet."

As you can infer by the cited cloaked source, this news is somewhere in between a rumor and a fart in the wind. The only info I gravitated toward was that Harrison Ford is standing-by for filming.

At least cook something! Jeez, Harrison...