SD <-> LA is also a lovely ride. Makes it feel like you're in one big city. Takes more than 2 hours, but it's city center to city center, and trains are so much more comfortable than any alternative.
Here are a few other commutable routes with maglev
NYC - Philly 92 miles
NYC - DC 225 miles
NYC - Boston 215 miles
NYC - Portland, ME 325 miles
NYC - Pittsburgh 380 miles
NYC - Cleveland 470 miles
Cleveland - Chicago 350 miles
St. Louis - Chicago 320 miles
Houston - Dallas 240 miles
Houston - Austin 170 miles
Dallas - Austin 200 miles
Seattle - Portland 175 miles
Las Vegas - Los Angeles 280 miles
But it would be great if all of those were connected by regular 200mph rails, 300mph maglev would be even better. I don't think there's the appetite for the level of investment either one would take.