Compare Google Maps Views.
Street Side is nice, just as Street View is. However, there is a lot more beautiful or otherwise interesting scenery in this world which could improve the Map experience. There is a lot of material available in the archives of the crowd and there are a lot of new shoots every day. Provide for cheap SkyDrive storage for imagery: photo, video, Photosynth. Provide a good map based tool to add latitude and longitude tagging (smartphone shoots will include them already). Provide copyright tagging, i.e. Creative Commons. Provide option to create Photosynth from a selection of photos. Provide option to share in Map. Provide option on all Bing Maps versions to easily access this imagery.
Make it even more attractive for the contributor by integrating Nokia Storyteller for WP8 functionality in SkyDrive.