Serious maglev development was done in Japan and Germany. That the former holds the world speed record (at 581 km/h = 361 mph) is due to a longer test line, the German technology (Transrapid) is more advanced. The Pudong to Shanghai line is the first and only commercial Transrapid, it reaches a scheduled 430 km/h (267.2 mph) even on its short strech.

As far as I know, the Shanghai Maglev does run (this November 30, its service was even extended), but rather empty (5 million passengers in 3 years): ticket is expensive, yet the end station is at a metro station in a suburb, so not very practical. The Shanghai authorities spared a tunnel under the city - and the project was expensive enough without it. Cost is also the reason plans to build a line in Germany failed so far (first it was to be Berlin-Hamburg, later across the Ruhr area, now to connect Munich with its airport - but even the latter could fail).

As I wrote in my earlier diaries, I am negative about maglev. It is a superior technology (tough not as superior as in some PR - the latest high-speed trains have come closer in acceleration, while have a better ride quality), but its track is very expensive. And another disadvantage is that while high-speed trains can continue to destinations on conventional lines (at least in Europe - but Japan also has three-track slow lines with Shinkansens), you'd have to build maglev tracks everywhere to offer similar service.

_{*Lunatic*, n.
One whose delusions are out of fashion.}