Things in .NET Framework 4 that every programmer should know [closed]

Answer 1

For ASP.NET programmers the ASP.NET 4 and Visual Studio 2010 Web Development Overview white paper gives a comprehensive overview of what is new in ASP.NET 4. For a series of articles on the most prominent and interesting changes I'd recommend Scott Gutherie's series of blog posts on VS 2010 and .NET 4 Series.