It is all one giant plan to win the midterm elections. Bush wanted to release the info in '03 but Cheney, Rove, and Haliburton urged him not to.
A reason for not disclosing this is not making terrorists aware they exist (and possibly prevent them from even looking from) until they are all secured.
Sorry....I just can't see the logic of allowing the non-release of this to make 3 whole years of the Bush administration a living hell of partisan politics in which it has become more and more difficult to pass his agenda.