I just went to the website about passports which is www.travel.state.gov and this is what is still says:
As early as June 1, 2009, the U.S. government will implement the full requirements of the land and sea phase of WHTI. The proposed rules require most U.S. citizens entering the United States at sea or land ports of entry to have a passport, passport card, or WHTI-compliant document.
This is only for land & sea, if you are flying out of the U.S. then you definitely will have to have them.
If you are not comfortable with not getting them, then go ahead & get them for your own peace of mind. We are going in September without passports.
Carnival Imagination 9/08/08
Carnival Imagination 1/31/05
Diana and Duane