Except for the other 40+ countries where it works http://www.google.com/intl/en/landing/transit/text.html#mdy

Here in Sweden, Google Maps have transit directions for buses, subways, trams and boats in at least the three major cities.

They worked in Nova Scotia, Canada.

Same goes for Toronto (GTA), Kitchener, Waterloo, Stratford, Ottawa, Niagara in Ontario, and Montreal and Quebec City in Quebec.

The transit app works awesome and is a bit easier to use then Google maps.

They work on iOS 5.0.1 in Kyoto, Japan.

Worked (and still working on iOS 5) in Sydney, Australia. There are posters up everywhere advertising the fact.

Works perfectly in Brazil (no buses though)