Apparently, a bunch of folks from various sites around the web were invited to the set of Kingdom. (FYI, I'm trying this terminology out: Raiders, Temple, Crusade, Kingdom).

Ain't It Cool News: Quint spots a certain character mentioned but not seen in Raiders (Kind of a spoiler)

SlashFilm: Apparently the current title has been the one for over a year. All others are red herrings.

Also: IGN, ComingSoon.Net, IESB.net