Will we in the UK ever see.?

No, it's not time to increase the limit. If it were 80mph, people would go 90mph. You see some real idiots on motorways as it is - tearing down the fast lane doing well in excess of the speed limit and getting angry with those drivers who do stick to the speed limit. They're a danger both to themselves and to other motorway users - all it takes is one blowout at that speed and not only are you dead (or maimed), but other people are too because of your stupidity.