As far as I can tell, at least for the moment the plan seems to be 4 tracks from RO to AF, and 3 tracks south of AF initially to Fredericksburg and eventually to Richmond. There is enough space in most places to put in a 4th track to Fredericksburg but that will require considerable additional bridgework and some land acquisition too possibly.
As George has explained many times the RF&P alignment is unlikely to host any HSR. 90 is going to be about the max. That is not going to preclude its electrification though at an appropriate point in time.
The other critical expensive project will be the Acca bypass for passenger trains to get from Staples Mill to Main Street station in Richmond. At one point some gave a thought to using the Doswell sub for avoiding Acca to get to Main Street, but that is so twisty that it was deemed quite unsuitable for even somewhat higher speed passenger rail.
Well, there seems to be no push for electrification south of DC. As to the HSR stuff, what is particularly interesting is that while RVR-CLT got a lot of discussion, in the Tier I report there seemed to be little or no improvement expected WAS-RVR. South of RVR, the discussion is almost exclusively diesel (with the exception of some random woolgathering down in Georgia), while further north this is the first mention I've seen of anything other than capacity upgrades.
I'm wondering...would $1.8 billion or so (what was applied for under Kaine) be enough to make any serious improvements on the 90 MPH limit? Per the studies done in the 90s, there was a suggestion that the use of tilt trains or increased superelevation might act as a workaround to the speed limits. Also, seeing as the 79 MPH speed limit trip time clocks in somewhere between 120-130 minutes WAS-RVR, what would likely be needed to generate a 97-minute or 90-minute trip time (as was in the plans from then)?