It is nice to see Windows Vista delivers new dialogs and controls. They are beautifier indeed. However, for .NET developers there is few resource to use. Even if you are using .NET on Vista, Vista Bridge is all that MS provides you.
However, Pedro M. C. Cardoso published his wonderful article on CodeProject.com. Using his library, the controls reaches you at once.
http://www.codeproject.com/vista/VistaControls.asp
The only problem is that you have to manually change all references to System.Windows.Forms to another namespace.
For me, the task dialog is the most useful piece even on Windows XP. Yes, the emulation is great!