David Hayden (a C# MVP) recently posted a good review of the FDG. Here is one notable comments:
Although I was originally worried that it would be more theoretical in nature and mainly apply only to architect types, such is not the case. It is a great combination of 1) best practices concerning fundamental API and class design; 2) great tutorials on .NET framework classes and the when, why, and how to use them; and 3) common design patterns for better manageability and extensibility of your frameworks.
The thanks for this comment has to go to Anders Hejlsberg who very early on in the process of formalizing the guidelines strong encouraged us to keep them very pragmatic and well grounded rather than theoretical.
Oh, and thank you Belgium – apparently we are the 19th Best selling computer book in the country. I am sure that Belgium is becoming a center for Framework design excellence!