So what cascades do people think will happen as a result?
Everything in the morning and evening peaks that isn't already 10 or 12 (except possibly the Aldershot-Ascot-Waterloo services; which may well join with/divide from a Reading at Ascot but that's hearsay for the moment) will be. That's the main priority
455s out; not necessarily for scrap; maybe diesel; maybe the Valleys
456s out; back to the pit of Hades from whence they came
458s out; probably Southeastern (I've heard Tunbridge Wells/Hastings rumours)
707s out; there's much speculation on here as to what'll happen to them; which may or may not include a pantograph; we quite simply don't know at this stage.
What's more interesting is the speculation as to what'll end up where. It may not necessarily be a straight replacement of the fleets above.