There’s an interesting interview with Ron Numbers in Salon: http://www.salon.com/books/int/2007/01/02/numbers. Here’s an excerpt.
. . . More recently, we’ve had the intelligent design movement. I know some people just see this as a new version of creationism, stripping away all the talk about God and religion so you can teach it in the schools. Is that true?
RN: There’s a little bit of evidence to support that. But I think that both demographically and intellectually, it doesn’t hold a lot of water. The intelligent design leaders are people, by and large, who do not believe in young earth creationism.
So they would accept the Earth’s being four-and-a-half billion years old.
RN: That’s not an issue with most of them. They want to create a big tent for all anti-evolutionists, even non-Christians. Whitcomb and Morris and the Creation Research Society wanted to create a tightly knit group of people who all subscribed to flood geology. The intelligent design leaders say it’s premature to insist on a particular interpretation of Genesis. This approach has really irritated many of the young earth creationists, who feel they’re being told by these intellectual leaders of intelligent design, “You’re just a divisive group dedicated to a particular interpretation of Scripture.” They are. But they’ve been very successful. And they’re not about to abandon their crusade to get people to accept scientific creationism in favor of some mushy intelligent design. . . .