Really? How come then they have the name 'High Speed Trains' - is it a name that predated the Meridians and has stuck?
Ha ha - sorry, that really has made me laugh.
As others have said, the term is almost interchangable with "Intercity 125", as the trains, when new in the 1970s and 1980s were known to travel at 125mph - faster than other trains at that time.
So in those decades, they were "High Speed Trains" but now nearly all new intercity trains are 125mph.
Interestingly, the term "Intercity" only really came to fame when the HST was built. Even though there were already intercity services (IE, fast trains between cities), the brand of the HST was known to be Intercity 125.
It's unlikely they would still use Neville Hill, as they only use it at the moment because the HSTs are there.
I wonder if when new trains are ordered/in play, whether EMT (or whoever) will continue to run trains from Leeds to London or anywhere else.