While much of the networking hype in the last several years has been about Software Defined Networking (SDN) and more recently Network Functions Virtualization (NFV), there are deeper underlying trends that will manifest in 2015.
Fundamentally, the promise of SDN that various vendors have evangelized is that of network agility. More often than not, though, the tried and true VLAN, a technology that predates the modern SDN hype, has proved to be more than sufficient to provide the agility than many organizations need.
What is difficult is managing policy across a distributed network, not just for quality of service and bandwidth, but for security and access control as well. Before the SDN hype, there was an era of hype around Network Access Control (NAC). While NAC hype has long since died down, the fundamental feature set is still valuable and is often just baked into networking best practices, hardware and software today. The same will likely be true with SDN increasingly in 2015. SDN, like NAC before it, will become a feature of broader network policy.