Wow, I can't recall ever seeing a mess like this before! I just hope there was no danger of a hacking of sorts. I just made reservations Thursday, and booked a very short hop on Friday to correct a mistake I made on a previous booking for which I already have the tix.
The troubling part is that lately we've been "trained" in a sense to wait until the day of travel and pick up our tickets then, both to save us the 10% refund fee, and to save Amtrak added logistics in the event of a cancellation or change.
In light of this, I think I might pick up my Friday tickets to Philly as soon as things get restored instead of waiting to the morning of.
By and large, I would *guess* that Saturday is the lightest day on the NEC, though I would imagine it is one of the heavier days in other areas (Chicago corridor trains, Heartland Flyer, etc.) so the impacts are not as bad as they could be, but I sure hope Amtrak clears this up within a couple hours, as the Sunday evening "rush" could really be a bad one.
Even after this is mopped up, there's still the fun of reconciling peoples' AGR accounts for those who rode merely on printed reservations.