Up until now, programmers had to understand the logical data model, know SQL, and write queries and stored procedures to get data to and from their C# (or Visual Basic) code. Then they had to convert the database data into some kind of object holders, the conceptual model of the problem space; for example, customers and orders.
The ADO.NET Entity Framework maps the logical database elements into a conceptual model for you, and you program against those. You can, but no longer have to write all of the SQL and ADO.NET plumbing. This change will let you focus your time and energies on the conceptual problem space.
I hope that the Entity Framework and LINQ will mean that programmers no longer have to spend an inordinate amount of time writing custom data access layers over and over.
Paul Kimmel is an architect for EDS and the cofounder of the Greater Lansing Area .NET Users Group (glugnet.org, Flint and East Lansing). Look for his book LINQ Unleashed: for C# and his upcoming book Teach Yourself the ADO.NET Entity Framework in 24 Hours (Sams, winter 2008). If you have a programming question, you can contact Paul at firstname.lastname@example.org.