In a thread on the link between ID and creationism, an interesting quote was posted, made originally by Robin Collins. I have expanded this quote slightly here.
Opponents of ID often argue that as a matter of methodology, scientific explanations should only refer to natural entities and processes, thus excluding reference to a transcendent designer. This position is called methodological naturalism. One cost that goes along with this claim is that if the hypothesis of a transcendent designer is excluded as a matter of methodology, then one cannot claim that science (at least when it theorizes about origins) purports to tell us the truth about the world, but only that science gives us the best naturalistic story. This, however, moves finding the truth about questions of origins partly outside the domain of science, to philosophy or theology.
This is an issue that I find very interesting. I disagree with Robin here.
Science does exclude transcendent designers from all hypotheses currently but this is because there is currently no evidence that any exist. No scientist can make the proposal that a transcendent designer should be a component of a scientific theory unless they can produce scientific evidence that there is such a being.