I will say that I don't quite see some services booming the same way Woody does...particularly those going past Harrisburg. Yes, the track improvements may be about the same for 8x new trains as for 1x, but I'm not sure the level of demand is there. I could see a situation where the state arm-twists those slots free...but only bumps service up to 3-4x daily service at most. You're more likely to see an aggressive ramp-up of Main Line service to Harrisburg before you see massive growth west of there.
I've said before that what is needed is new-build from Lewistown (west of Harrisburg) to State College, which is the big population center between Harrisburg and Pittsburgh -- roughly following US 322. It would require a significant base tunnel (maybe as much as 10 miles), but the gains are likely to be worth it. The line would be electrified to State College. NS would likely require capacity expansion Lewistown-Harrisburg before allowing electrification.
This is viable on its own as an extension of the Keystone Service. There is no complete expressway route from that area to Philadelphia, so I expect the State College station would have a very large catchment area. And then there's the college students!
Continue west on rehabilitated track Tyrone, and reroute the Pennsylvanian. You bypass Huntingdon, but you gain State College. You've just removed Amtrak from NS's mainline for a large distance, which they'll appreciate, and you can build faster track to gain time. This also allows for the relocation of the Lewistown and Tyrone stations off of the NS mainline into better locations downtown in the actual cities. Probably with grade separations for stuff like the street trackage in Lewistown.
I'm not sure whose attention I have to get to promote this idea. Most of the Keystone West and Pennsyvlania HSR studies have been abominable and incompetent. This might be a $2-3 billion project, but it would add a valuable station, and connect areas faster than an expressway (which does not exist anyway). The consultants for Pennsylvania have come up with more expensive projects which are a lot less useful.
There needs to be advocacy for a "Harrisburg-State College" HSR project, but I don't even have a spiffy name for it.
It is the logical next step after the Keystone improvements.