This has been the plan for the last 2 years. It's not new news. I know we are on track at Port Everglades (I have clearance there).
Here is a recent interview but you an google and get references back to 2002.
Remarks by Secretary of Homeland Security Michael Chertoff and Professor of Public Policy and Communication at George Mason University Frank Sesno in a Conversation
Fairfax, Virginia
George Mason University
April 26, 2006
[snip]
Mr. Sesno: We've got some great questions here, so let me try to tick through a few of them. As of today, what percentage of total daily cargo containers are vetted upon entry into the U.S.? This is port security.
Secretary Chertoff: One hundred percent are screened, meaning we know what is inside. We get information about what is inside each container from manifests and other loading documents.
Of those that are screened, based on our intelligence and the information we have about the container, the shipper, and the destination, we inspect 100 percent of those that we deem to be high risk. We will have by the end of October approximately 70 percent of the containers coming into the United States coming through radiation portal detectors at our ports.
Mr. Sesno: Seventy percent of all containers.
Secretary Chertoff: Correct. By the end of next year, it will be virtually 100 percent of all containers coming in through radiation portal detectors.
[/snip]
But read this carefully. What is this reallly telling you?