Leon,
I think this is a very interesting request, just as we know, different requirements needs different base maps. Here are some base map options that can be used in SilverlightEdition:
1. Google Map. There are two kinds of Google Maps API that you can take into account. GoogleMapsLayer on server side and built-in client GoogleOverlay. Both they use the Google Static Maps API, I think all works fine except the 1000 request limit per day. The limitation makes the development inconvenient sometimes.
2. Bing Map. That’s fine except a little slow I think. It’s from MicrosoftMapsLayerExtenstion on server side. We also have upgraded to latest version.
3. ThinkGeo MapSuite WorldMapKit Wms server. It’s kind of WMS server which covers all the places in the world. I think this works pretty well, there is built-in WorldMapKitOverlay in all our products. You can get it easily. I think this is a good choice if it fits your requirement.
4. Yahoo Map on server side. I don’t think this is a good choice.
5. Open Street Map. The server side can be used now, and the client side APIS will be coming soon. It works with Projection 900913.
6. All the available WMS Server.
All the above is the options that you can get in SilverlightEdition, if you have some good ideas please let us know.
Thanks,
Johnny