Besides all the issues with a WAS-ATL day train - needs state funding, does not run to NYP, inadequate station in ATL, etc - Why would it use Superliners, which are in short supply? Besides, NC is planning high level platforms for the Raleigh station, I believe some of the other stations in NC on the Piedmont corridor either have or will be getting high level platforms. The Piedmont corridor is part of the eastern network after all.I would think that the very next train that Amtrak should add - if they could somehow add a new (short) route, would be a daily train - WAS to Atlanta. It only requires two train sets, and each set could be two Superliner coaches and one Sightseer Lounge - with food service on the lower level. One coach could be a coach/baggage. So three cars (6 total) are needed - to start this service. Plus two engines.
The train would serve WAS, Culpepper, Charlottesville, Lynchburg, Danville, VA, Greensboro, NC, High Point, Charlotte, Western SC stops, and Atlanta (with a night arrival around 9 PM). The total population is over 10 million people along that route. Plus you have connections to the NEC.
Two coach cars and one Sightseer lounge? That is not much capacity. If you think people are going to take this daily train, it should have the capacity to handle them and sell enough seats so the train service does not lose huge amounts of money.
With Georgia just getting started to get involved in the planning and studies for the SE HSR and with Atlanta having a limited station, all this talk about providing daytime service to ATL is way ahead of the situation. The focus should be on improvements in VA and NC. Get many of the VA and NC planned track projects and service expansions in place, then talk about extending daytime service to ATL.