Are we forgetting that every new technology product market follows this path? You start off with lots of little start-ups trying to innovate and provide solution for a need - real or perceived. Some of them are successful, some are vapor ware, etc. Eventually the market consolidates, hopefully to the few products that work AND INTEROPERATE.

Network Access Control is definitely needed for most environments. Letting just anyone plug into your network, get an IP address via DHCP, and then start exporing your net or spewing attacks is a problem. But you can't stop it without NAC, because you will always have vendors and contractors stopping by and plugging in - even if you have procedures that say otherwise.

The problem is: there is need, but no product maturity. So-called solutions right now tend to be monolithic architectures, and if that is the way it stays then you will buy Cisco or Microsoft because they own the network and the systems. And trying to sell management on a key access technology from a startup is unlikely to be successful. It's the same old challenge - nothing new here.