[Webinos proposal] onLost callback when found but not yet bound service is lost. onServiceUnavaialble and onServiceAvailable callbacks for bound services. [Opera/CableLabs proposal] readyState changes fire back to web page's network service objects. readystatechange events occur on a network service object when the service becomes available or unavailable. servicesAvailable attribute is used to monitor general number of services of the authorized type currently available in the user's network(s). [Google Web Intents] No service status monitoring in the Web Intents API itself but guess that this could be handled in the specific protocol for the specific Action. [Google Web Introducer] No service status monitoring in the Web Introducer API itself but guess that this could be handled in the specific protocol for the specific intent type. [Feature] 
Service status monitoring