There are signs that Amtrak management is realizing that putting all their eggs on the regional corridors may not be the best idea. They've not been having much luck partnering with states, and then there's the proposal to drop the 750 mile rule down to 500 miles. The later implies interest in creating new long distance routes. Granted this could mean more daylight LDs like the Palmetto, but it could also lead to night trains (leave after dinner, arrive before breakfast or lunch) between city pairs. Sleeping cars are actually quite lucrative and help subsidize passengers in economy so they aren't going away unless the LDs themselves go away.