The New Yorker article states that Everett published the article in Cultural Antrhopology (Fall, 2005). As far as I could tell, the author meant CURRENT ANTHROPOLOGY Volume 46, Number 4, August-October 2005:
http://www.journals.uchicago.edu/CA/journal/issues/v46n4/054006/054006.html
(for those of us who have access through academic institutions and such)...
Arash:
There is a link to a free copy of the paper in this Language Log post, along with brief discussion of the article and a link to a response paper by some generative linguists casting doubt on Everett's claims.
http://itre.cis.upenn.edu/%7Emyl/languagelog/archives/004387.html