I emailed Ford about this. Here is the response:
Robert,
Thank you for your email in regards to SYNC. The ability to add navigation is an option that Ford is entertaining for the future. At this time there has not been any formal announcement made on when or if this will be offered. Please continue to work with your dealer, they will inform you when the feature is made available.
Sincerely,
James
Ford Motor Company
SYNC Support Center