On saturday Rainer Stropek, Co-Founder and CEO of software architects,spoke about Framework Design Guidelines at the conference See# Party in Switzerland. Here are the key topics that Rainer covered in his session:

1. How to decide whether to make or buy a certain component/framework?
2. Common naming rules in .NET/C# libraries
3. Live demo of StyleCop and Code Analysis (FxCop)
4. Design principles for making libraries self-describing
5. Example: Library design in LINQ (extension methods, functional parameters, etc.)
6. OO-Design: Class or structs? How/when to use interfaces? Etc.
7. Correct use of collections
8. Exceptions in class libraries
9. Why unit testing is important?

You can See Sharp Party 2010 - Framework Design Guidelines.