What are the future plans for Cisco that will help maintain their status as the leading manufacturers of networking devices in the market?

Making more of software products and becoming a software networking compnay more than hardware. Hardening the quality their products and reducing the number of software defects they make.

Cisco always try to serve market in a better way, launching Radar technology soon, introducing new ways of QoS, have secured telecom core standard of 99.999% uptime (overall only 5mins downtime in a year on 24/7/365 running) known as five-9s standard. Many protocols Cisco have are still not made by IEEE or other for the Standardization (the one of the reason companies choose Cisco). In future launching real time data in the energy sector also. Making things better to have network simpler Using an Architectural Approach to Strengthen Systems and many more

CISCO will enables a new and programmable network that can anticipate actions, stop security threats in their tracks, and even learn to solve previously unsolvable challenges.

For Cisco, the network has become code. Just as early developers monetized the iPhone ecosystem, developers that act now will pioneer dramatically more powerful apps in IoT, analytics, AR, VR, data science and other areas incomprehensible to us now.

Have you heard of Software Defined WAN?

Very weird question which was asked in a very wrong time. There are couple of facts that you are not aware of or simply you have not heard of. As you might not know, Cisco has been ranked as a software company now because of SDN. Cisco is no longer a hardware-only vendor, thanks to Virtualisation. You're worrying about the maintability of a big vendor like Cisco, so don't worry. They're just doing very well. Instead, you should worry about yourself and keep up with their tech train more than worrying about a hairy monster like Cisco.

If your point from the question is worrying about your future with Cisco, then the question is now making more sense. Cisco is not going to fall overnight and they are still the networking leader. I find their products appear in movies, TV series, commercials,..etc. This means they are getting even bigger. Cisco also embracing SDN and started to manufacture controllers. They already programmed all their network devices to speak the OpenFlow language. Although SDN is being adopted slower than expected, Cisco is the major key player of SDN.

Just proceed with your Cisco credentials and you'll be just fine. !!

It's future plan to enhance security products and it did that already by launching FirePower 

. Intent based networking solution, This enables a new and programmable network that can anticipate actions, stop security threats in their tracks, and even learn to solve previously unsolvable challenges