I think rail is a viable alternative for business travelers given the following criteria:
1. Distance is at 500 miles or less.
2. Frequency of service to meet business needs (is there a train that'll get you to the meeting and back? )
3. Proximity of rental cars and ease of renting upon arrival. (Renting a car usually entails getting a cab from the train station to the airport or nearest rental location. Not that convinient, but Amtrak gives you $20 if you use their preferred vendor, Hertz)
However, for long distance, I don't think the train is realistic. If I had a meeting in California, it'd take me 3.5 days to get there on Amtrak. If we had 300 mph train service (didn't Siemens and the SCNF set a land speed record in France last year?) non stop between the east and west coasts (without having to change at O'Hare, err Chicago), then rail would be more attractive to the long distance traveler.
The Ohio Hub system looks pretty realistic. For us, it might even be a real option, since my wife has family in Columbus. We could board a train in Lancaster, travel to Pittsburgh, change trains and continue on. However, it takes 4.5 hours to get to Pittsburgh on Amtrak, and the trip to Columbus really is only a 6 hour drive. I'd estimate the train to Columbus is at least another 3 hours from there.