One question that I'm asked repeatedly is, "Is LINQ dead?" The quick answer is, NO. The more appropriate question is "Is LINQ to SQL dead?" That one is a bit trickier, particularly after some of the blog posts from the data programmability team regarding their emphasis moving forward for LINQ to SQL and the Entity Framework.
My take on it is that LINQ to SQL is in a similar situation to Winforms. Both are still supported and have teams dedicated to them, but don't expect much in terms of new features, rather the focus is on bug fixes. The main development focus for new features is placed more on the Entity Framework and similarly WPF. For those who love taking SAT tests, you can think of it as
LINQ to SQL : Entity Framework :: Winforms : WPF
Proof of the point, Damien Guard, one of the people on the LINQ to SQL team, just posted a list of 40+ changes that are coming for LINQ to SQL for .Net 4.0. Looking through the list, most of the items are bug fix items and not feature enhancements.
Of the list of items, the biggest change I see is specifying the text parameter lengths. Adding this eliminates some of DBA's performance concerns in terms of query plan reuse. This is one area that DBA's have focused on in terms of the performance issue and was an unfortunate oversight in the initial release.
There are a number of larger features that people continue to ask for that are not being included.
- Support for more complex table to object relationships. This is really the point of the EDM, so I don't see this ever making it into LINQ to SQL.
- Ability to update a model from database schema changes. Again, the EDMX designer supports this, so I wouldn't hold your breath.
- No support for SQL 2008's new data types, including the Spatial types, HierarchyId and Filestream. If any of the features were added, I would expect this to be included at some point.
Damien's list should be proof that LINQ to SQL is not dead, but it isn't going to receive significant enhancements that you may want. Check out the 2010 beta and see what changes are there for yourself and give feedback to the teams before it's too late.