WCF Data Services to the rescue
Developing Windows Phone 7 Applications that integrate with SharePoint data have a lot more in common with developing .NET Managed Applications for the desktop than writing SharePoint Pages or writing Silverlight applications that live inside SharePoint. That is to say while developing custom list templates or Silverlight parts inside SharePoint, these applications have direct access to the SharePoint Context. We will not have that ability in Windows Phone 7.
Although we can't use the managed DLL's that were provided for Silverlight applications in Windows Phone 7, we still have access to the same information and functionality. It's just going to be a lot more work to use them.
The client object model communicates ...