This article from Mike Fratto at Current Analysis is great observation. Here is my view on the core topic:
Networking vendors need to embrace homogeneity—that’s my first bit of advice—and present the most homogenous network to the virtual environment they can. By being homogenous, enterprises can swap out networking with far less disruption than having to deal with proprietary or advanced features. Presenting a homogenous face to the virtual environment also means network vendors can reduce the friction that occurs in replacing an existing vendor. Stickiness—that property making a vendor switch difficult—can come from heterogeneous hooks that make switching technically and needlessly complex or it can come from better feature sets. The former annoys customers while the latter makes them happy. Money from an annoyed customer spends just as well as from a happy customer, but a happy customer is far more valuable.
This reinforces my view that network services being deliver in hardware is no longer required.
I think that Mike is making the point that the physical network must be homogenous which equals simplified, low disruption and accessible by API .
But we still need quality and robust network connectivity. We need TRILL, SPB, L3 ECMP and multi-gateway FHRP solutions to build Ethernet Fabrics. We need integration points between the overlay and underlay for new technologies like VTEP.
And the network must be absolutely trustworthy, reliable and, above all, predictable. It must work exactly as expected when changes are made. Devices must reboot reliably and survive code upgrades without risk.
Features and services are derived from the overlay or software-only devices. There is no place in the physical network for load balancers, firewalls, network taps, MPLS and so on. These simply build problems into the underlay that makes it risky and unreliable.