Danko Kozar | Software Architect and Developer Real geeks don't need Facebook TM

Essentially the C# 4.0 language innovations include:

• Dynamically Typed Objects.
• Optional and Named Parameters.
• Improved COM Interoperability.
• Safe Co- and Contra-variance.

http://software.intel.com/en-us/blogs/2009/03/30/the-c-programming-language-version-40/

... and more syntactic sugar.. :-)