Passengers excited by the prospect should keep in mind that things move slowly in the railway world
Just remember that the Class 43 (HST 125s) were just a short-term stop gap but are still in use 40 years later. Of course, the best is the Class 483 trains on the Isle of Wight line: Originally built in 1938! And the new class 230s are actually refurbished tube trains originally built in 1980.