The Internet's infrastructure shows severe limitations when an optimal end user experience for multimedia applications should be achieved in a resource-efficiently way. In order to realize truly user-centric networking, an information exchange between applications and networks is required. To this end, network-application interfaces need to be deployed that enable a better mediation of application data through the Internet. For smart multimedia applications and services, the application and the network should directly communicate with each other and exchange information in order to ensure an optimal Quality of Experience (QoE). In this article, we follow a use-case driven approach towards user-centric network orchestration. We derive user, application, and network requirements for three complementary use cases: HD live TV streaming, video-on-demand streaming and user authentication with high security and privacy demands, as typically required for payed multimedia services. We provide practical guidelines for achieving an optimal QoE efficiently in the context of these use cases. Based on these results, we demonstrate how to overcome one of the main limitations of today's Internet by introducing the major steps required for user-centric network orchestration. Finally, we show conceptual prospects for realizing these steps by discussing a possible implementation with an inter-network architecture based on functional blocks.