Since maglevs can't be used with normal rails, they've been slow to catch on, and the only commercial maglev train operating today is in Shanghai (shown above). They have reliability issues as well, as the U.K.'s Birmingham Airport found out when it had to replace a short maglev line with a conventional system in 1995 because of technical problems.
Funnily enough, the top speed of this breakneck maglev doesn't quite match the maximum warp of France's doubledecker TGV train, which set a record of 357.2 mph earlier this month. Maybe the Japanese and French should get together and pool their high-speed rail tech to create a supersystem that uses the best of both. Hey, it works with with cuisine