Is Intelligent Design Testable?

In a prior post on the failed predictions and un-falsifiability of evolution, a visitor left this interesting comment:

How can intelligent design (ID) be tested? Any supposed problems with the theory of evolution are not evidence for ID. ID must stand on its own and provide a framework for testable hypotheses that scientists (both religious and non-religious) can perform worldwide in repeatable tests. If ID cannot be tested, it should not be taken seriously as an explanation for the amazing diversity of life on this planet.

I thought this to be a fair and important question, and worthy of its own dedicated post. Here, I intend to argue that direct experimental validation is a false expectation for the kind of claim that ID represents, that the burden of proof belonging to ID is highly debatable, and that experimental work can, in fact, be done which can speak to ID.