I think you're going to see multiple systems with centralized control exert a partial influence (as opposed to complete control like Puppet/Chef) over systems.

I think you're going to see multiple systems with centralized control exert a partial influence (as opposed to complete control like Puppet/Chef) over systems. DNS is a pretty good example: nobody thinks of configuring a DNS server on a system as setting up a "controller", but in some sense it controls an important aspect of the system's behavior. So does NTP. Another example is the SDN-inspired "Wi-Fi sharing" platform Anyfi.net that I'm working on. It allows you to configure an "anyfi controller" e.g. on your home Wi-Fi router, but that "controller" only has a say in how the spare bandwidth and "extra SSIDs" on your router are used. It can set up Wi-Fi networks and tunnel out the raw 802.11 frames to an endpoint anywhere on the Internet, but it can't do anything that impacts your security or steals significant portions of your bandwidth. In that sense it's somewhat like DNS, but with even less security implications for the "controlled" system.