Check out the new managed debugger sample on the .NET Framework developer center.

The sample demonstrates how to use the CLR debugging interfaces and also shows how to use the CLR MetaData, Symbol Store, and Process Publishing interfaces. It also demonstrates the use of advanced debugger features implemented in Whidbey, like edit and continue.  The sample demonstrates how to use the CLR debugging interfaces and also shows how to use the CLR MetaData, Symbol Store, and Process Publishing interfaces. It also demonstrates the use of advanced debugger features implemented in Whidbey, like edit and continue.