ADO.NET Data Services with inheritance and navigation properties
Last week, I speak for the WSC about ADO.NET Data Services (aka Astoria) and I said that it's really great, particularly with EF.
I always think that but I see a non covered scenario which is a big big shame in my opinion:
When you have inheritance between your entity types, you can't have navigation properties in your derived ones. All your navigation properties must be on the base entity type (which is a nonsense).