According to him, the fourth "Shrek" film is in the works, scheduled for release in 2010. While the fifth is being planned as well, it will be the last one in the franchise.
"It's a finite story, has been from the beginning and I think that's part of its integrity, part of its strength, that we're not thinking this up as we go," said Katzenberg.
"Ultimately we will come back to understand how Shrek arrived in that swamp. We will reveal his story."
From what we have heard, there is still a "Puss in Boots" movie and a "Shrek" TV Christmas special which will run every year. If these films continue to succeed like they have, I have a feeling Katzenberg will be taking his words back.