For much the same reasons that I don't consider Roger Daltrey an impartial source to explain the influence of The Who, I doubt anyone's memoirs will add to the historical interpretation of recent events. Heck, the LRB had an article that reminded me newspapers aren't a very good source for the historical record (section beginning "Having learned to write news, I now distrust newspapers as a source of information...").
Thinking about the qualitative research that I've read, you almost never see memoirs used as evidence, because individuals cannot get past self-interest, especially when that self-interest allows them to rehabilitate public opinion concerning them. As an example, a few years ago Duke had a reasonably famous person who has produced work on Rescuers during the Holocaust give a lecture; their research includes a heavy component of interviews with those people in order to discern their motivations. The researcher showed video clips from some of those interviews, where it became apparent (among other issues) that they had assimilated much of the post-WWII discourse on their actions to explain what they did. As research, that borders on the useless. What will be most useful in constructing the future picture of the decision to fight the Iraq War will be documents that have not yet been declassified. All this to say, don't expect to see an equivalent of Essence of Decision anytime soon.