A French speaking reader contacted Dunod, the publishing company that listed the Nikon D800 book, and they insist that the book will be released in March of 2011 - here is their answer, for whatever it's worth:
Il s’agit d’un livre qui va normalement paraître en mars 2011. Voir le lien ci-après: http://www.dunod.com/loisirs-essais-bien-etre/loisirs-scientifiques-techniques/audio-photo-video/photographie/obtenez-le-maximum-du-nikon-d80"
which translates to something like:
This is a book that will normally be available in March 2011. See link below: link"
Update: here is the follow-up email from the publisher (thanks Andre):
"I emailed them again saying that the book title says D800 but the information in that link is about D700. And they told me the information is about the D700 but the D800 is supposed to be the D700 replacement. Their answer: Effectivement, les informations concernent le D700. En tout cas, le Nikon D800 est censé être le remplaçant du D700."