The often sometimes accurate CHUD has got a few rumors on the next Indiana Jones film. (If they're true they're definitely spoilers, so be warned.) Take everything that's said about the movie with a grain of salt, but there's also this:
Interestingly, there have been rumors of a video game tie in being released next year with the title Indiana Jones and the Staff of Moses; I checked with other sources and while I can?t confirm anything, this seems to be a stand-alone adventure and does not reflect the title or storyline of Indiana Jones IV.This is the first we've heard of a title for the new game, but it does at least correlate with the extremely limited info we have on the story, which will feature a mystery of "biblical proportions." I don't know where he got the title from, but I'd say it's only probably fake, rather than assuredly.
Update: I've learned that Indiana Jones and the Staff of Moses is the name of an old work of fan fiction (notable enough, apparently, to be adapted into a fan comic) which kind of throws doubt on the veracity of this leak. Still though!
Staff of Moses sounds too similar to the Ark of the convenent. Plus, what would suck a staff do? Create water springs? Big whoop!
It's funny you should mention the artifact being too similar, because this is what George Lucas has to say about the artifact in Indy 4 (from an old article):
"I discovered a MacGuffin," Lucas said. "I told the guys about it and they were a little dubious about it, but it's the best one we've ever found. ... Unfortunately, it was a little too 'connected' for the others. They were afraid of what the critics would think," Lucas said. "They said, 'Can't we do it with a different MacGuffin? Can't we do this?' and I said 'No.' So we pottered around with that for a couple of years. And then Harrison really wanted to do it, and Steve said, 'OK.' I said, 'We'll have to go back to that original MacGuffin and take out the offending parts of it and we'll still use that area of the supernatural to deal with it.'"
The ark really has no story impact in the first film other than something for the characters to be chasing... and a tidy way of killing the bad guys at the end. The item in the second film REALLY has no impact on the story, other than providing a situation for children to be enslaved. And the third film? Well, it comes close, but really the movie is about the father/son relationship rather than the grail itself.
A true McGuffin, like the Maltese Falcon, is completely meaningless...the statuette has got an infamously shallow history, and it's simply the thing that all the characters want. OK, so it's worth a lot of money, but that's not the reason Gutman and co. want it. It's important only because the characters believe it to be so.