Found out yesterday, quite by accident, that Indy IV is apparantly scheduled for June 2006! Apparantly Titled Indiana Jones and the Lost Continent, there’s a teaser trailer available at ifilm.com, together with a brief synopsis that has our Indy lured out of retirement to find Atlantis.
The trailer itself is pretty closed; it’s got the Indy music with the camera panning over the fedora, pistol, and whip, all of which are placed on a map, and then cuts to a sequence of a martial-arts chap doing his stuff with swords, before getting punched by who we assume is Indy (it’s done in a first person perspective, so you don’t see!) The trailer ends wth “06.06”.
Not too tricky to fake a teaser like this; neither Empire nor IMDb have any more details than this, although Empire does list a June 2006 release date, so I guess we just have to wait and see.