This is going to force some Facebook user conceptual model evolution, to prevent geolocation-related info over-sharing
There are, of course, complications, which leave the geolocation- and local-services start-up community with plenty of questions about how much of their data they will have to share with Facebook if they tap into the new APIs. And additionally, Facebook's tendency to garner bad press with regard to privacy may make some of them wary of getting involved.
But it's likely that they will have little choice. Facebook is the biggest force in the social Web by far, and it's about to be the biggest force in geolocation, too.