Word is that Yahoo will soon disable the JSON output format for their geocoding API, the REST based geocoder will remain. What does this mean? Well the JSON api is what makes tools like our batch geocoder possible. Without it I would need to use a server side proxy, meaning requests going to Yahoo would be coming from our web server instead of the end-user IP. This means the 50,000 per day limit would be set on the server, only 50,000 geocodes total for batchgeocode.com.
What I do know is that I did see this coming, no way is Yahoo going to throw out a free geocoding API with a JSON output format and not think about the possibility of turning it off someday. It was inevitable that a service like batchgeocode.com would be created, and that would inevitably mean that the data providers would complain about such a service. Perhaps this is why the JSON output format was never mentioned on the Yahoo geocoding API reference page?
Still Yahoo is interested in providing geocoding services in their maps, it’s what differentiates them from the competition. So geocoding isn’t really going away its just getting reworked a bit. The whole farm is no longer available for free, but the house still is.