I've been chatting with Vish over email.  He made me aware his approach to getting SQL 2008 & Virtual Earth to play well together using GeoJSON.  I actually didn't know about GeoJSON.  Thanks Vish!  Check out his post explaining the approach:

http://viswaug.wordpress.com/2008/06/02/sql-server-2008-virtualearth-made-easier-and-building-a-rest-api/