Nats airports probably will be sold off
Whilst this might or might not be true, there's an equal possibility under SESAR (Single European Skies) that HMG could accept IAA, AENA or DFS for example, taking over the NATS en-route operation (there would be absolutely no reason, operational, political or legal why this couldn't happen). Whilst your salary would probably be protected under TUPE, your pension would not (the same would apply to the NATS airports business if sold off). Therefore, in making any decision if you're enabled to do so, don't take these factors into account.
It's true to say that there is more demand for area ATC skills on a world-wide scale, but conversely, if you don't necessarily want to work abroad but at some point in the future, you get disillusioned with the area side of things, there'd be no alternative to NATS for you within the UK if you're an area-only rated controller.
You pays your money and takes your choice...
