Atom, commenting at William Dembski's blog uncommondescent, made the following case for Intelligent Design. I have paraphrased it slightly, but you can find the original in the comment section here.
1) It is a given that complex, integrated, functional machinery exists.
2) There are two logically possible causes for 1: A) intelligence, and B) non-intelligent forces of nature and chance.
3) Non-intelligent causes have not yet been empirically demonstrated to produce complex, integrated, functional machinery. This has only been assumed (see just-so stories).
4) Intelligent causes have been, and can be, empirically demonstrated to cause such machines. (Computers, cars, aircraft, etc.)
5) Therefore, intelligence is currently the best and only explanation for 1. Until another causal class can be empirically demonstrated as a viable cause, Intelligent Design is the default position.