The end of the general purpose operating system

First up, a bit of clarification. By general purpose OS I'm referring to what most people use for server workloads today - be it RHEL or variants like CentOS or Fedora, or Debian and derivatives like Ubuntu. We'll include Arch, the various BSD and opensolaris flavours and Windows too. By end I don't literally mean they go away or stop being useful. My hypothosis is that, slowly to begin with then more quickly, they cease to be the default we reach for when launching new services.So note that this isn't about desktop workloads, but server workloads.