Since it is a recent topic on the french mailing-list, I began some weeks ago to map the bus lanes in Aix-En-Provence, because I believe that OpenStreetMap could take a real advantage in the field of public transports, where google maps is actually wrong in my own opinion (despite their effort to develop a free specification of handling this kind of datas, see http://google.com/transit for more information).
In France - and I think it's the same everywhere -, there are a huge number of different companies which handle the mission of transporting people, but no web application does exist yet to compute and harmonize this whole mess, and a lot of these companies are only giving some PDF in their official websites.
How long before an application where one could say "I want to go here from there, and I won't pay more than x euros for that" ? :-D Of course it is not in the field of OSM to gather the transport timetables, but once we have the bus lanes, I guess that at least 90% of the work is done.
PS : Thanks to the guys behind http://www.öpnvkarte.de/ , your mashup is really awesome !
PS2 : Why not a batch import of google transit-compliant companies ?
PS3 : Still around 15 lines to map, good night ;-)