A study of mitochondrial DNA a few years back stated that Neanderthals probably had not mated with our H. sap. sap. forebears.
Having known quite a few H. sap. saps. in my life, I found this conclusion dubious, even in a world before the invention of beer goggles. Plus, there were all those Jean Auel books and, Shiva knows, they made a cage full of rabbits in heat look like the eunuchs' dormitory at the Topkapi on a slow weeknight.
So the link from CNN.com on Friday to this Time.com article came as not much of a surprise. Humans are generally known for trying to mate with anything they're not currently fighting or eating, and I can't see why this should have been any different in the Middle Paleolithic than it is today.