It will be not only one OS, instead it will be three tools: Boss, Manager and Worker.

Boss - tool to watch all rigs in a farm and give them "orders" like reboot or install a new Worker or drivers or change pool and whatever.. Also it will keep images of Worker OSes and all settings for every rig. This tool can be on the rig or on a separate computer.
Manager - "middle-OS" that will run when rig boots, bring the new Worker OS to rig (if Boss says so), change video card ROMs, setup miner, restart and boot to Worker.
Worker - actual mining OS with drivers and software. Includes restart watchdog.

Three setups are possible: One rig, Many rigs (one of them contains Boss) and Farm (Boss on a separated computer).

This schema lets owner to have full control of everything in one place.