In the world of Anything-as-a-Service (I will leave the acronym to your imagination), Network-as-a-Service is not a new term. In fact, it even has its own wikipedia page which will tell you it has been used for many years now, well before the current set of service related terms in IT have become popular.
Like most high tech industries, we get somewhat carried away when we have some new terminology and quickly overuse and overload them, watering them down to be meaningless or at least highly confusing. But when you cut through the clutter a bit, the as-a-Service terminology most certainly articulates a shift in thought process and behaviors on how we provide and consume IT resources.