The problem with intelligent-design theory is not that it is false but that it is not falsifiable: Not being susceptible to contradicting evidence, it is not a testable hypothesis. Hence it is not a scientific but a creedal tenet—a matter of faith, unsuited to a public school's science curriculum.
I just heard someone put that quote to Bob Dutko on the radio. Bob's response is "But you don't mind that abiogenesis is taught in the class room." Is abiogenesis taught in the biology class as if it were true? I doubt that. Unfortunately Bob's opponent was not a type of person that seemed like he was expecting a debate and he wasn't good at pressing his points.
Apparently Will's comments resulted in a Nightline interview where he squared off against Cal Thomas. The transcript and audio are here. Dembski also replied here. He says ID is testable because you can test if Darwinian mechanisms can explain something like a bacterial flagellum. I suppose in the same way my theory that Zeus casts lightning bolts is testable because you could disprove it by looking at static. So the Zeus theory was positively scientific until Ben Franklin came along.