Here is what to look out for in debate:
Conflate intelligent design with creationism. I'm not sure how much longer this tactic will work because the public and press are now catching on to the difference, but as long as there's mileage to be obtained, go for it. Emphasize science as a great force for enlightenment and contrast it sharply with fanatical religious fundamentalism. Then stress that intelligent design is essentially a religious and political movement. Generously use the "C-word" to confuse intelligent design with creationism, and then be sure to liken creationism to astrology, belief in a flat earth, and holocaust denial.
- Argue for the superfluity of design. This action point is also getting increasingly difficult to implement simply on the basis of empirical evidence, but by artificially defining science as an enterprise limited solely to material mechanisms, one conveniently eliminates design from scientific discussion. Thus any gap in our knowledge of how material mechanisms brought about some biological system does not reflect an absence of material mechanisms in nature to produce the system or a requirement for design to account for the system, but only a gap in our knowledge readily filled by carrying on as we have been carrying on.
- Play the suboptimality card. For most people the designer is a benevolent, wise God. This allows for the exploitation of cognitive dissonance by pointing to cases of apparent incompetent or wicked design in nature. I believe intelligent design has good answers to this objection, but the problem of evil is wonderfully adept at clouding intellects. This is one place where skepticism does well exploiting emotional responses.
- Achieve a scientific breakthrough. Provide detailed testable models of how irreducibly complex biochemical systems like the bacterial flagellum could have emerged by material mechanisms. I don't give this much hope, but if you could pull this off, intelligent design would have a lot of backpedaling to do.
- [And finally] Paint a more appealing world picture. Skepticism is at heart an austere enterprise. It works by negation. It makes a profession of shooting things down. This doesn't set well with a public that delights in novel possibilities. In his Pensées, Blaise Pascal wrote, "People almost invariably arrive at their beliefs not on the basis of proof but on the basis of what they find attractive." Pascal was not talking about people merely believing what they want to believe, as in wish-fulfillment. Rather, he was talking about people being swept away by attractive ideas that capture their heart and imagination. Poll after poll indicates that for most people evolution does not provide a compelling vision of life and the world. Providing such a vision is in my view skepticism's overriding task if it is to unseat intelligent design. Good luck.