For what it's worth, I think it's rather unlikely that TTWMNBN will agree to a Bloggingheads-style debate. He would want it to be public. And he might decide that Eliezer isn't high-enough-profile to be worth debating. Remember: for him, among other things, this is propaganda.

Entirely agreed. There's a chance such a debate could be arranged if the book is a success, though.