I have seen this article in Danny Simmons' blog. He positions the Entity Framework versus various Data Access technologies like ADO.Net, LINQ to SQL and nHibernate.
He first differentiates it from ADO.Net and LINQ to SQL by explaining EF is doing mapping. Then he differentiates it from nHibernate explaining that EF is not better at doing mapping but it is different because it relies on EDM, thus it makes a distinction between the process of mapping queries/shaping results and building objects and tracking changes. This would make this layer reusable in different contexts. It means the same conceptual Data Model (Business Model) could be reused in different scenarios. I really need more details about that real benefits, besides the fact Microsoft intends to widely use EDM internally. We understand why EDM is important to Microsoft, we don't really get the technical benefits of this approach for the users.
Please see how Julie Lerman explains in her blog why Microsoft is taking care of the nHibernate community trying to avoid the flame war which happened with Hibernate in the Java Community.
Also see reactions from readers in both blogs.