Let me give the W3C's original quote a little more perspective...
Again it's perspective as I have not seen the W3C suggest that divs and spans be used. Remember that divs are block level elements while spans are inline level elements. I think (Ted) that you confused the fact that I suggested them both at the same time without enough clarification.
HTML 4 as far as the validator is currently concerned allows <body><span> while XHTML 1.1 will not validate with inline elements in the same manner.
So if you're using HTML 4 you are allowed to use inline elements in the body without the usage of parent elements, at least according to the validator. I'm not sure what the W3C says about this specific topic.
I would assume an XHTML 1.0 transitional/strict doctype would also perhaps require inline elements to be inside parent elements to validate?