There seems to be a merging (at least semantically) of the Cascadian dark Ale and the Black IPA.
A real black IPA should use the huskless varieties of dark malts (carrafa special, etc) for their zero diastatic qualities without the bitterness that comes from scorched husks....whereas the Cascadian dark seems to be evolving, and only recently even given style guidelines, and anything seems to go.
I love the Cascadian dark ales being brewed up here in the NW, I brewed one with simcoe, chinook, citra, centennial and cascade that was outstanding!