As for your last paragraph, I genuinely believe that ATCO's wont be replaced by computers for a very very long time, if ever. You might want to visit some units and then you will realise why, particularly if you go on a bad weather day (ie plenty of CB's, turbulence and icing). Its much more likely that pilots will be replaced completely by computers first, and I cant see that happening either even though the technology is available to do it already!
The technology to replace ATCOs by computers exists. No-one has put it all together because it is not economic (yet), but it is technologically possible IMHO.
There is a much greater military/economic advantage to eliminating pilots so they have been done first, but ATCOs could be replaced. In fact the increase in usage of autonomous UAVs will make it more likely because it will weaken the public perception of the need for humans in the loop.
Its probably a little way off yet, but someday a successor of barron will compare wage costs with the one off costs of building an automated system and get a different answer from today