1. A method for providing geo-location proximity updates to a presence system, the method comprising: intercepting a mobility management message associated with a mobile subscriber, wherein the mobility management message includes one or more network specific identifiers (NSIDs); determining, based on the one or more NSIDs, a geo-location proximity descriptor; and communicating a presence update message including the geo-location proximity descriptor to a presence server in a presence system, wherein the presence server stores presence information associated with the mobile subscriber, wherein the presence information includes a status indicator that conveys an ability and willingness of the mobile subscriber to communicate with at least one presence service watcher that is subscribed to receive the presence information associated with the mobile subscriber, wherein intercepting the mobility management message includes intercepting the mobility management message on one of a core signaling link interface, an A-interface, and an A-bis interface.