Loree Griffin Burns has a guest post at Cynsations on nonfiction genres. I had thought about this type of thing in the past, but only in relation to true nonfiction--say, the difference between types of essays. Loree includes fiction in her analysis, if the fiction has a nonfiction element, as in historical fiction and science fiction.
I totally agree with Loree that the term creative nonfiction has caused confusion. I have read nonfiction that included totally made up conversations, for instance. I was confused. I remain confused about that.