Clearing up Mapping technologies in .NET vNext
David and Andres speculated on the positioning of the upcoming mapping technologies in .NET.
The problem domain your application targets has a mismatch with the already existing data model. In this case, the ADO.NET Entity Framework is the right choice.
The existing data model matches the problem domain your application targets. You don’t require mapping between these two models. Linq to SQL lets you directly map to your existing or new data model.