As of git tonight Salt can support a master of masters interface, this means that a single master can now control many sub masters in a transparent manner. This means that we can create many topologies of master control with Salt.
The idea being that you can have many Salt masters, say for specific clouds, clusters or environments, and then have a higher level master that can control publications made on the masters. The best part is that the return data is transparent, so the master of masters will look like it is a master of just a ton of minions, but the master's work will be spread across the specific masters.
The transparency also means that a master can be both a direct master of minions and a master or masters, or that you can have a master of masters and minions or a master of masters of masters etc.
This will be the showstoper feature of 0.9.0, hopefully I can reign in my crazy life enough to have 0.9.0 out soon.
Thanks for following Salt, a lot of exciting stuff is happening right now.
-Thomas S Hatch