The demanding requirements of new real-time and mobile multimedia group-based applications (e.g. IPTV and video-conferencing) motivates the research for novel and efficient network architectures, able to fulfil service requirements and increase user experience. Multicast, despite its scalability issues, is the most suitable network technology for the delivery of multiparty content. Context-awareness is taken as a key feature in Next Generation Networks, enabling a management framework with a more comprehensive knowledge of the network, application and user. The challenge is how to use the available knowledge towards service personalization and network efficiency. This paper presents and evaluates an architecture that aims to provide personalized session content delivery to multiple mobile users, integrating different access and transport technologies. The architecture relies on an end-to-end contextaware communication framework able to dynamically react and adapt to context changes, through session and network reconfiguration. Our focus is on the transport network part, addressing a new level of scalable multiparty content delivery through the concepts of abstract multiparty trees and overlay nodes. The results show that the concept of abstract trees reduces the network reconfiguration complexity while still guaranteeing end-to-end QoS.