Results of My Completely Unscientific Internet Survey on the word "Network"
Q: What do you think when you hear the word "network"?
Which is about what I expected - an emphasis on the lower layers (2-3) of the stack, some crossover at the transport layer (4) and diminishing mindshare at the higher layers (5-7).
That bodes somewhat poorly for technologies attempting to change "the network" because the focus ends up on the increasingly commoditized L2-3 space and the specialized, value-added network services at L4-7 drop off the map.
There's an inflection point in the stack at L4 that changes the economy of scale both technologically and financially, which is likely why cloud continues to focus on black-boxing network (l2-3) infrastructure and investing less and less up the stack where the value lies but requires more compute and interference (operational overhead) such that the customer cost must necessarily increase to compensate for investment in building the services.
And then there's a whole bunch of technical reasons why that inflection point is important, and why it's really hard to commoditize (and extract the same economy of scale) non-standardized traffic into general-purpose services.
In other words, we're just beginning to get to the good parts of cloud ... and SDN will gain faster maturation/adoption simply by virtue of being able to coattail on many of the same benefits and concepts.