1. A method of managing one or more subscription application services provided for use by endpoint devices associated with gateway devices located at a plurality of respective user premises, each gateway device at a respective user premises being connected between a respective local area network at the premises and a wide area network, the method comprising steps of: providing a service management system, said service management system enabling service providers to manage services through at least one of the gateway device, enabling automatic authentication, configuration, and management of gateway devices and automatic discovery, authentication, configuration, and management of endpoint devices via said gateway devices for access to services, managing application service subscriptions accessible by gateway devices and endpoint devices, and providing service updates to gateway devices, wherein the gateway devices provide gateway access to the service management system over a wide area network and at least some server functionality for service delivery to one or more endpoint devices, including client devices at respective customer premises, over the local area networks within the customer premises; based on a service subscription of a customer associated with one of the gateway devices, sending information to the one gateway device indicating configuration data or software currently needed for the one gateway device to implement server functionality for an application service or a feature of an application service subscribed to by the associated customer, through the wide area network for communication to the one gateway device; receiving a request from the one gateway device, indicating that the one gateway device needs the configuration data or software to implement the application service or feature thereof; and responsive to the received request, sending configuration data or software, through the wide area network for communication to the one gateway device, to carry out at least one of: enable the one gateway device to deliver the server functionality for the application service or the feature of the application service to one or more endpoint devices implementing client functions related to the application service; manage endpoint and user access to third party application services; enable, control and manage diverse endpoint device-to-endpoint device access and sharing of services within the customer premises; and allow third party service provider access to endpoint devices to provide additional services including at least one of content, troubleshooting assistance, repairs and updates.