Note: There is a number of corporate projects I've been involved with from 2005 till today, but cannot put them online because of their nature.
http://langnetsymposium.com/2009/talks/23-ErikMeijer-LiveLabsReactiveFramework.html
http://msdn.microsoft.com/en-us/library/aa479314.aspx
http://technet.microsoft.com/hr-hr/magazine/2005.01.sessionhijacking%28en-us%29.aspx
http://www.codeguru.com/csharp/csharp/net30/article.php/c13799
http://www.dnrtv.com/archives.aspx
http://www.codeplex.com/AutoMapper
http://www.dimecasts.net/Casts/ByTag/ReSharper
Essentially the C# 4.0 language innovations include:
http://software.intel.com/en-us/blogs/2009/03/30/the-c-programming-language-version-40/
... and more syntactic sugar.. :-)