From the Variety interview:
"Nor is Lucasfilm's exit from features instant or absolute. "Indiana Jones 4" is still in development. "Steve (Spielberg) and I are still working away, trying to come up with something we're happy with. Hopefully, in a short time, we will come to an agreement. Or something," Lucas said, without a great deal of enthusiasm."
I don't know about you guys, but if it's October 2006 and they 'are still working away, trying to to come up with something we're happy with', I don't see them starting production in mid-2007 as they previously stated in their Empireonline interview.