The Future of Networking Professionals
Unless they can write software that plugs in fiber jumpers, configures new switches, troubleshoots routing loops, and maintains documentation, I strongly believe networkers (as we know them) will be around for another 15-20 years.
That doesn't change the fact that you'll have to continually learn new technologies as they come out, but SDN seems to be just an overlay on an underlying network.
It's a convenience factor for complex data center implementations. SDN is to the data center as MPLS/MPBGP is to WANs.