Cognitive dissonance is not your friend.
These documents are not translated yet (according to the OP). So, if they go public now, and it turns out that these documents say exactly the opposite of what the President wants, he's called a liar. If he doesn't release them immediately (read: before they are translated) then he's hiding something and they must be faked. Of course, if these documents turn out to be supportive of the president, the opposition will simply claim the same thing as some of the above posters: Bush made all this up. No, wait, he's too stupid to do that. Oh, it must have been Rove and Cheney. But, why are these just being found now? Um, if you're asking that question, you are one of two things: 1) Just looking for any way to discredit something that shakes what you believe (ala cognitive dissonance) or 2) Not understanding that even though you get news 24/7, it is not possible to search an entire country in 1 year.