Did the first Americans come from Down Under?

According to this: Did the first Americans come from Down Under?

Native Americans cannot claim to have been the first people in America . Apparently new research suggests the original inhabitants of America may in fact have come from what we now known as Australia, in other words whiter than the natives we know? Whereas the people that hitherto we have thought of as native Americans came overland from Siberia. The former group apparently has been dated to 12 700 years ago, whereas the oldest accurately dated "native" American skull was only about 9 000 years old.

Okay, perhaps a real "anthropological hornet's nest," but, does anybody want to go there? What of the socio-political ramifications?

On the other hand, I think the article is suggesting the first group was wiped out by disease though. In which case, isn't this just semantics? So they were here, and they all perished, which is as good as not being, right? I reckon none of this should matter, notwithstanding the smug and fascinating! factor. Afterall the lot that came here with and post Columbus found these people here. End of story.