The official word from Cool Toy Review states:
During Celebration IV, one of the guys at LEGO wasn't being mindful of the crowds, or more precisely the two ears of said crowd, when he let it slip that they will be producing toys for Lucasfilm's upcoming Indiana Jones IV feature film. While details are a bit sketchy, it is safe to assume that these will be shown later this year. Hats off to trusted CTR friend Nick for the heads up.
Finally, we can pull the legs off of Harrison Ford. Sure, we could have done that upon purchase of the Millennium Falcon playset, but you don't want to pull the legs off of Han Solo. He's still cool.
Indiana Jones 4 opens May 22nd, 2008.