http://blogs.msdn.com/usisvde/archive/2008/12/01/language-enhancements-in-c-4-0-and-beyond.aspxBased on the .NET Framework 4.0 we will see new and exciting features. The theme for future C# versions is to incorporate more features based on the industry trends: Dynamic Language Support: In the industry see more and more use of dynamic languagesen-USCommunityServer 2.1 SP1 (Build: 61025.2)