My previous post was an out-of-nowhere post on WPF (Windows Presentation Foundation), a technology not many developers know. Although you can easily know all there is to know "about" WPF on the web, learning to "use" WPF is more important and you need the proper resources for that. WPF applications can be developed in both Visual Studio 2008 and Expression Blend 2 and developing a complete WPF app requires expertise in both. Here are some resources which you can use:
A guided tour of WPF
The official WPF site
The MSDN resource for WPF
Here's my description of WPF:
WPF (Windows Presentation Foundation) is a programming model within the .NET Framework which allows you to build rich, compelling user interfaces. The highly-rated Silverlight platform for the Web is nothing but a subset of WPF. You can compare it to Windows Forms, although there is a world of difference between the two. In fact, WPF is best understood when compared to WinForms.
In a WinForms app, there are 1 or more "forms" which constitute the user interface. Each form is an instance of a class which derives from System.Windows.Forms.Form and its UI and codebehind are both in C#. So, there is a Form1.designer.cs and a Form1.cs both containing partial declarations of the class Form1.
In a WPF app, there are 1 or more "windows" which constitute the interface. Each window is an instance of a class which derives from System.Windows.Window. While the codebehind is in C#, the UI is in what is called XAML (Extensible Application Markup Language). So, there is a Window1.xaml containing pure XAML and a Window1.xaml.cs containing pure C#, both containing partial declarations of the class Window1.
XAML is an HTML-style language which allows you to layout the controls of a window just as you would layout elements on an HTML page. XAML provides what WinForms cannot provide - rich and highly customizable user experiences. XAML provides for custom ListBoxes, binding controls to XML and CLR data sources, animations through storyboards and plenty more. In fact, you will get a better idea once you actually start creating a WPF app in Visual Studio 2008.
Apart from Visual Studio 2008, there is a software called Expression Blend 2 which allows you to concentrate only on the UI through XAML. Its intuitive interface allows you to do whatever you wish with the user interface. WPF is a very good and recommended thing to learn for developers. Code hard, go pro!