Well, the New York Times is reporting on the NYC transit authority's test of new diesel hybrid busses. Finally, a real advance in bus technology! No doubt these busses will be expensive and this will make it hard for transit authorities to adopt them as the fuel savings will probably not justify the cost. But when the social cost of emissions from city busses are accounted for I am confident they will be a sensible choice. So here would be a cash-for-clunkers program I could actually support: the government helping fund conversions to hybrid bus fleets for big city transit systems.
As an aside as hybrid cars are great in city traffic and diesels are great on the highway in terms of MPG, it seems obvious to build a hybrid diesel car, no? Apparently they coming and when they do, I think I'll have found my perfect car...and a Peugeot no less, super-cool!