Soilguy, you might find this interesting:

http://cogweb.ucla.edu/ep/Templeton_02.html

Of course there is nothing specifically Neanderthal covered but it does show hybridising between Out of Africa and pre-existing human populations.

In my observation the belief in replacement by a single movement "Out of Africa" in influenced by biblical stories about species, including humans, descending from a single couple. We know evolution involves whole populations. Have you had intimate contact with some subspecies of the Judeo-Christian genus of human belief?