Wow another article pointing to the existence of humans in North America way earlier than once thought. This whole idea of traditional Archeological evidence and the written history of ancient humans being somewhat wrong is very interesting to me.
Graham Hancock is a British writer and Journalist who have interests in ancient civilizations and altered states of conciousness. His book Fingerprints of the gods was a very interesting read and since reading that I've attempted to stay up to date on new evidence pointing to facts which show Humans might have a much more interesting past than traditional histories tell us.
http://www.bibliotecapleyades.net/egipto/fingerprintgods/fingerprintgods.htm
Some of these ideas are related to the Atlantis myth (or not myth) as well as how old some of the major archeological sites really are (Sphinx for instance).
Here's a link to Graham Hancocks main page as well: http://grahamhancock.com/