Following this and that, I decided that I want to create my own set of questions, I'm not on par with Scot, but anyway... :-)

WinForms:

• What is the purpose of Contorl.InvokeRequired property? What are the situations that you would use it?
• Why Form.WndPrc is a protected method? In what cases would you override it?
• What is the difference between inheriting from Control and inheriting UserControl? When would you do either?
• What does it mean to set Thread.IsBackground = true?
• Can you use Data Binding without Datasets? If yes, how? If not, why not?

General .Net Stuff:

• When would you subscribe to the Thread.UnexpectedException?
• When would you subscribe to AppDomain.CurrentDomain.UnhandledException? Can you prevent an application termination by subscribing to this event?
• What is the Thread Local Storage Pattern and when is it applicable?
• What would happen if an exception is thrown in the first method of a multi-cast delegate (a delegate that contains several methods)? What would be the return value of such a delegate if an exception is not thrown?
• Name three places where the BCL uses the Strategy pattern.
• How do I call my old VB code that contains all the business rules?
• When should you use ClsComplaintAttribute? What are the differences between the CLS and the CLR?
• What is the preferred way to concentrate strings? Why?
• What is the difference between Array and ArrayList?
• When would you override Object.Equals() and what else do you need to do when you do that?
• What is an AppDomain?

General Programming Info:

• What is a regular expression and when is it used?
• What is XPath and when is it used?
• What is working set and why is it important to application performance?
• Is it important to preserve locality of reference? Why or why not?
• What is paging? What are the implications that it has on scalability?