Read a little piece in this week's The New Yorker. It mentioned the London charge, which Londoners evidently really like...also a successful plan in Stockholm.
Since the NY legislature would have to pass a bill on this, it's chances seem remote at best. It sounds great though...one of Bloomberg's plans would put the congestion pricing money (est. $400mill/annually) towards improving the subway and bus service.
"But, as the mayor pointed out, New York, a flood prone coastal city, is vulnerable to one of global warming's most destructive...and almost certain..consequences: rising sea levels. If New Yorkers won't change their behavior, then it's hard to see why anyone in the rest of the country, or for that matter, the world should, either. The congestion problem will, in that case, find a different resolution. Who, after all, wants to drive into a city that's under water?"