Dave Bouwman just wrote up his findings on bringing ArcGIS Server web service (using the WMS service and SOAP API) into Virtual Earth. Another great example of using a hosted web service with your existing GIS projects.

I’m pretty sure the ESRI Developer Summit will be full of folks wanting to know about using Virtual Earth in their ESRI web applications and doing it outside of the Web ADF. The REST API cannot come soon enough IMO for those who develop using the ESRI platform.