An interesting post has arrived on the Ado.net team blog with regard to the future of LINQ to SQL. Although not coming outright and saying it, it seems that LINQ to SQL is likely to be deprecated in the future in favour of Entity Framework.
“We’re making significant investments in the Entity Framework such that as of .NET 4.0 the Entity Framework will be our recommended data access solution for LINQ to relational scenarios”
So this leaves the question, what will customers who have implemented LINQ to SQL do for long term support. I would like to see Microsoft provide clear guidelines and tooling in order to help those unfortunate ones migrate their existing software forward. The good news is that the awkward gap between LINQ to SQL and EntityFramework now seems to have been resolved.