Will we have a KML feed that loads photos based on the viewport? Probably. It’s no coincidence that our flickr.photos.search API takes a bbox parameter for searches while Google Earth automatically added a bbox parameter to urls it loads with a NetworkLink. The intention (well mine anyway) from the start has always been that you should be able to point Google Earth directly at Flickr’s API and just let them get on with it.
flickr does kml output. a good start. now if yahoo maps started using kml. kudos to flickr for adding the KML link officially. now they only need to efficiently serve more than 20 photos 🙂