Yeah, the CHUD rumours. Didn't they also say something about Abner? I didn't believe them at the time coz they said a lot of things (and still don't believe half of it) that have still yet to be proven. True, they said Shia was a greaser and were right. However, unless I'm getting mixed up now they also said that Indy IV would be to do with the Ark's return. Something I personally don't hold a grudge against but I know a lot of Indyfans (you only have to look at this board) that certainly hate the idea of the Ark again.
I don't think it'll be the Ark again. It's not quite right however the game is supposedly called "Staff of Moses." Definitely related to the Ark. However, I have a theory that the film may be something to do with the Headpiece instead, which would explain those similar serial numbers on the official site. Perhaps the Headpiece can be used to find some other MacGuffin. I don't know what, but that's just my guess.