Trace into .NET Framework codes

I am finding lots of interesting things these days. I was reading Scott Gutrie's blog and found out a link from there to the other blog http://blogs.msdn.com/sburke/archive/2008/01/16/configuring-visual-studio-to-debug-net-framework-source-code.aspx where I found the details about tracing into .Net framework codes. Now we will be pressing F11 more than before.