Publish/Subscribe systems are nowadays largely accepted for coordinating applications over wide-area networks, whereas they still suffer when applied to mobile environments. In fact, the typical tree overlay network implementation of the event service, which provides scalability in the context of wide-area networks, fails when a run-time reconfiguration is needed. This might happen when dealing with the dynamic and mobility characteristics inherent to the pervasive environments. In this proposal, we address such an issue by envisioning a context-aware approach in order to build and maintain the dispatching tree overlay with respect to the context sensed through the environment. The resulting distributed control system optimizes on the energy consumption aspect, which is the key cost measure for a mobile environment such as sensor networks.