As stated in the MyGIG manual, the website (www.chrysler.com/mygig) which currently forwards to the 2007 Sebring should be made public by the end of January 2008.
See below for the email I received from Chrysler Customer Service:

See below for the email I received from Chrysler Customer Service:
Well, he only mentions that the owner instructions will be posted, but fingers crossed for updates, add-ons, etc.Dear Tyle,
Thank you for contacting the Chrysler Customer Assistance Center
regarding the MyGIG updates for your 2007 Dodge Nitro.
We understand your concern and appreciate the time and effort you took
to write to us.
We are aware that the /mygig page is redirecting to Sebring vehicle
information about MyGIG. This problem is in the process of being
corrected. MyGIG owner instructions are expected to be online by the end
of January. You may want to check the site again at that time. We
apologize for any inconvenience.
Thanks again for your email.
Sincerely,
xxxxxxx xxxxxxxxx
Customer Service Representative
Chrysler Customer Assistance Center