If the Government handles it like they did the sale of Sydney or Bankstown airports, it will be a disaster.
Can you honestly see it going any other way?
It's not like there will be co-located ATC services wanting your business, like the airlines can do. So even if you 'privatise' ATC towers/TMA/Enroute into UPS/ECS/RS; can you really get benefits from competition?
They are single businesses with no competitors at what ever particular location is being privatised; it could only possibly go the way of SACL etc. Maximise their profitability within the contraints defined by the laws; is this a benefit to industry, honestly could you possibly say yes what would be different by privatising ATC; if you make it not profitable who would buy it?
The example of Ardmore is facinating; a non profitable aerodrome with huge costs (relatively, like BK) replaced by a not for profit business model resulting in reduced costs mostly due to overheads and services being provided by those that want/need the service; but nethertheless not getting the control service it used to. Does this (still?) happen outside the ATC Tower hours at Jandakot (CAGRO)?
An Australian example could have been when Port Headland Tower closed, if the areoclub there moved in and provided CAGRO or similar (an offer at some stage), but lets face it that's nothing to do with privatisation and everything to do with service vs dollars.