Actually trains are never going to compete with NY to LA, airplanes are going to almost always make more sense for such a trip.
So the focus should be more regional in nature.
Anyways I agree that we should worry more about getting 'moderately quick' trains. The current Amtrak service is horribly slow: its just borrowing the tracks from the freight train companies so on a typical ride you have to get off the main track and wait for a 100-car coal train to mosey on by once or twice.
Its essential that passenger trains have their own tracks. I suppose if your making that sort of investment, you might as well go a little bit farther and make it high speed.