If you haven't seen it, Mike Pizzo, an Architect for Data Programmabilty at Microsoft, has a series of blog posts describing the interesting history and evolution of ADO into what it is today.
In his last post he describes the Entity Data Model (EDM) and how client views are exposed through an ADO.NET data provider extended to support a query tree representation. He also explains what happened to ObjectSpaces, which I found particularly interesting. He goes on explaining how LINQ is supported in the Entity Framework (ADO vNext) and that they both will be featured together in the next Orcas CTP (due in Feb/March). One thing that I asked Mike is what kind of guidance can he give on using EDM over DLinq and when we can see tooling for EDM in Visual Studio.
This next Orcas CTP is very exciting because it will have all the pieces finally together. LINQ, ADO vNext, and WPF tooling are my personal interests.