Both our intelligence reports and admissions of former scientists indicate that there were such programs, and this leads many to believe that enough information about those programs is being disclosed in the declaration documents so that reasonably trained scientists will gain a great deal of specific knowlege about the production of these weapons for nations that do not currently have said capablility.
It is unlikely that a personality such as Saddam Hussein would be in voluntary compliance with the previous UN protocols that were set forth at the end of the Gulf War. This means that those programs and weapons still exist in some number, somewhere.
The question right now is whether or not Hans Blix has the motivation and expertise, not to mention the sheer number of inspectors, to enable him to complete the assigned task. My gut says "no".