The Open Geospatial Consortium's current Geospatial Web efforts define standards for delivering 2D map data over the internet. What the Web3D X3D Earth initiative can contribute might be something like a "Web Viewpoint Service" - the ability to query and deliver geospatial data from a perspective other than a 2D bounding box with a zoom function - i.e. the 3D Geospatial Web....
Open Standards for Real-Time 3D Communication
A nonprofit organization that develops and maintains the X3D standard--a 3D file format and runtime specification that is open, royalty free and ISO ratified for transmission of 3D data over networks.