Well Dave, he did pay for the pizza in advance, so they really had nothing to lose with this stunt. If they missed the train, the delivery guy could just eat the pizza.
As for pulling this off with Amtrak, I think it would be very possible in many locations. It's all about knowing the schedule and being able to project your arrival at a station, preferably one with easy access to the platform for the delivery guy. Actually, I wouldn't be surprised if someone hadn't done it already, and just not gone public with it the way this guy did.