I agree, WiFi is not going to save Amtrak. It's almost always the worst possible transportation option available in terms of cost, quality, comfort, time, etc - for any and all start and end points, not just NYC/BOS.
A bus might make more sense on a shorter trip (like the aforementioned NYC to Boston example), but I think there's a real sweet spot for taking the Amtrak on trips longer than, say, 4-5 hours on the bus but shorter than a 2 hour flight (excluding baggage/security/travel to and from airport time).
Especially Amtrak's business class, which is extremely comfortable, with plenty of space for a computer and stretching out, quiet and spacious enough to get work done, and usually only an extra $20 or so.
I admit my fear of flying sways me toward Amtrak when a flight might make the most sense, but to me a bus is almost always the worst possible transportation option available.
Agreed that Amtrak is a much more pleasant experience, though - much less stop and go, generally higher reliability of arrival time, more legroom, smoother ride.
I wonder what it would take for Amtrak to be able to compete on price with the competitive bus lines in the northeast corridor. Subsidies on rails comparable to those on the interstates, perhaps (or getting rid of the interstates' subsidies and making them self-funded)...