Thanks for that. I get the impression that the cameras are going digital, and that bit is believable.
The bit I don;t believe is the lower action limit for when no variable limit is showing, and that article doesn't say the Highways Agency confirmed thats the case. After all on Pistonheads there have been requests for anyone who has received a NIP following a flash from those cameras when no variable limit was showing, and so far no one has owned up to receiving one.
Anyway we'll see what happens!