I didn't have In Socrates' Wake bookmarked on my laptop, so I haven't been keeping up with it over the summer. Trying to catch up, I came across this old post and discussion thread there. It even has the stuff about physics making the country worth defending rather than helping defend it. Two other things strike me about it: 1. we philosophers don't seem to be very good at articulating a shared sense of what philosophy is for, and 2. several people defend philosophy by linking it with questions to do with ethics and religion.
Given the kind of danger faced by philosophy programs (alluded to here, for instance), #1 seems like something we ought to address. That is, if philosophy programs are going to be cut (as they have been at Middlesex University, e.g.) unless they seem more relevant, then we ought to try to present a united front of relevance. It might not be too late to emphasize the connection between critical thinking and philosophy. Ethics seems to me to be promising too: shouldn't every school offer a course like Michael Sandel's Justice? Once you've taken Critical Thinking then you might try Logic, and then maybe Philosophy of Language. After Contemporary Moral Issues, why not Ethical Theory and then Meta-ethics? And after World Religions why not Philosophy of Religion and then Metaphysics? The nature of causation can seem very abstract as an issue, but probably seems more relevant after you've wrestled a bit with the cosmological argument. This might partly explain why Intro Ethics courses sometimes seem to be more successful than general Intro to Philosophy courses.
That's how I would try to build and sell a philosophy program anyway, making sure along the way that students learned at least something about the history of the subject. But I know some people would see this as both pandering to the bureaucrats and missing much of the real meat of philosophy, which they see as dealing with problems in metaphysics, epistemology, and philosophy of language. It's that conception of philosophy that makes it seem irrelevant though. Which might be what kills it off in the end.