LINQ Changes in January CTP (aka December CTP)
There are some changes happened with LINQ Project with the January CTP. The namespace names like System.Xml.XLinq or System.Query are no more there. Namespaces got changed to System.Data.Linq and System.Xml.Linq.
Other than namespace and api changes lot of .proj file and C# syntax changes have happened.
For detailed information visit Charlie’s BLOG