At this point, Google has not responded to my inquiries, so I think it is fair to say that the solution will be to do the routing outside Google, and then display the results in either GoogleMaps or GoogleEarth. We have been talking with them since they were Keyhole Corporation, and hopefully will have a Fusion Server here at Metro to publish our own local data through the GoogleEarth interface. We are an ESRI shop, so we are also thinking of an ArcIMS route solution that would be distributed via a browser based application. Though, given the recent momentum in the open source community – propelled by the Google API – I’m pretty certain that an open solution will appear very soon. Hopefully driven in the Portland region by our better datasets.
Hope this gives you a little insight into what is happening here. I’m really excited by the potential for this type of application, and I think the enthusiastic response we have got from the community for just publishing the linework to LOOK at in GoogleEarth is an indication of how strong a demand there is out there for cyclists to be able to plan their rides, and explore bike routes from the Net.