That scene is both a testament to Japan's commitment to high-speed rail, and a reminder of how far the U.S. lags. The fastest train Amtrak's got, the Acela, tops out along its route from Washington to Boston at around 150 miles per hour. And the gulf between these two speeds is important: It's the difference between a trip from D.C. to New York that feels like long-distance travel, and and one that feels like a transit commute.
If we had a train on the East Coast that traveled the speed of Japan's new maglev, you could commute from D.C. to New York in under an hour. You could get there about as fast as it takes some local commuters to travel from one end of the Silver Line to the other.
The implication is that truly high-speed rail could make intercity travel akin to intra-city commuting (maybe not between Denver and Seattle, but along the mid-Atlantic or within the Midwest). You could work in Washington and buy a cheaper home in Philadelphia. You could hire workers in Boston for your firm in New York.
Speed, in other words, changes geography. There's a potential downside to this — fast cars (and highways) made suburban sprawl possible by opening up whole new territory within commuting distance of downtown jobs. But fast trains also have the potential to further knit together the economies of nearby cities just too far apart for commuting today. They have the potential to open job prospects, or to expand your pool of affordable housing.
Of course, the cost of a ticket on-board would affect who can actually afford to commute out of state instead of just across town. But Japan is clearly thinking about the benefits of bringing cities closer together through transportation. The ultimate route the Central Japan Railway Company is currently building will stretch from Tokyo to Nagoya. And it will cut the ride between the two all the way down to 40 minutes.