The fifth generation (5G) of mobile networks is envisioned to support new applications having demanding requirements, such as low latency and high reliability, which is the focus of this article along with enhanced traditional mobile broadband and massive sensing. Different approaches have already been proposed to achieve low latency while guaranteeing high reliability. However, the challenge of efficient resource utilization remains. In this article, concepts for a flexible and low-latency-enabling mobile network architecture are presented, along with strategies for staying efficient. The work is put in perspective with respect to ongoing standardization activities. Finally, future visions for network management architectures and 5G's impact on economic aspects are discussed.