Dreher is right when he discusses the appeal pantheism has in our culture, but it was not popular as de Tocqueville had suggested; rather for the "spiritually" inclined mild intellectual sort in our culture, pantheism is a tempting sort of compromise religion. We can have God, but God has the same lack of positive meaning as metaphysical materialism, it is just that it gives us some warm feelings.
What baffles me is that Dreher could post this material and then rehash lazy claims that panentheism is some sort of Orthodox doctrine, and not a distinction without difference dreamed up in the 19th century German academy. And I mean, "without difference" because for the mass of persons, there is no difference, and even the distinguished definition does not hold well for the idea that the idea can somehow be saved for Orthodox usage. Journalistic skepticism should have suggested that the popularity of "panentheism" as a term describing Orthodox view on creation (often by non-Orthodox authors doing us no favors) is due to a need among mild intellectuals in our culture to envision "Eastern" Orthodoxy as being this sort of mysterious religion–those strange, chanting, hirsute folk–who have a religion that is just like they are.
To use some broad strokes, the distinction between pantheism and panentheism (when one is actually intended, and the latter is not simply used as a supposedly acceptable epithet for the former) is one between metaphysical monism and dualism. In the first case, there is one spiritual (or, rarely, material) substance, god. For the latter, there are two substances, god's mind/soul/etc. and his "body", i.e. everything with extension.
A professor of mine once called panentheism the lazy out for Christian philosophers of science. This sort of identification of the universe as just a body God is getting used to in some ways was a way to smooth over the philosophical road of reconciliation, despite its vacuousness. To be fair, these writers are almost all Protestants and Catholics, and the only Orthodox working in that neck of the woods I can think of who uses the term–Alexei V. Nesteruk–does try to bracket away many bad implications of the term, but the necessity of that makes you suspect either A) the utility of the term at all or B) the honesty of the writer in giving these caveats. (I do not claim to have enough of a grasp on Nesteruk to make a guess as to whether he is doing B. I've only read one work of his, Light from the East
That said, I think that Nesteruk's sort of "yes, but" case for the term is probably the best that can be made for Orthodox use of it, but that brings up questions of what makes the use of terminology alien to the Church, valid.
I mentioned before wanting to write a more thorough post on the topic. I have come to admit my own current short-comings, and this will have to hold in its place for now.