Learning to create applications requires many skills, beyond simply learning a programming language. Developing applications using the .NET Framework requires learning many skills specific to the .NET Framework, and this event focuses on a few of those important intermediate skills.
You’ve learned the basics of XAML. You can build simple applications, but you know there must be more to using Silverlight creatively. You’re right—Silverlight 4 is a big topic, and even building the simplest applications requires some detailed learning.