Again, the article is sourced anonymously, so it'll probably be best to take this with a pretty large chunk of rock salt, but it sounds plausible enough. God only knows what Lucas will come up with to explain the Bermuda Triangle, though. Third Reich holdouts operating laser towers? Crystal skull statues attempting to kill people with vicious knowledge-beams? Darth Vader having been trapped on a Caribbean island after falling into a black hole and using Force Pull to wreck aircraft out of pure spite? Stuff's source says that the film will be a more traditional Indy film, rather than relying on large amounts of CGI, but hell, Harrison Ford is going to be pushing 70 by the time this movie comes out; it'll be interesting to see what they can get him to do without breaking all of his ribs.
Ford might not even care about a broken rib or three, though; he, Lucas, and Spielberg split almost 90% of all the profits Crystal Skull made after its first $400 million. It went to almost double that number at the worldwide box office, so they each pocketed well over a $100 million from the theatrical release alone. And they only had to nuke the fridge to do it. The question is whether Crystal Skull squandered enough franchise goodwill to seriously hurt the profits of a fifth movie. I guess we'll (maybe) find out in 2012!