In reply to the original poster;
I had heard rumour that ATSA roles within Swanwick were being axed, I believe with the eventual goal of all such posts being eliminated. As I understand it this is more to do with the ATSA role becoming less necessary due to new technology than it is to do with the economic climate. Perhaps someone who currently works there has a more detailed insight and/or time frame?
I can't imagine the location of your son's home will have a significant bearing unless it is having a detrimental effect on his work (i.e. turning up late for work, being tired due to long periods of travel etc.)
There will still be ATSA positions at many airfields (both inside and outside NATS) after the Swanwick positions are gone, but I believe vacancies are currently few and far between as well as being highly competative.
Sorry the outlook is a little bleak :/