You can create Silverlight applications in the WPF Designer for Visual Studio as easily as you can create WPF applications. The familiar features of Design view, XAML view, and the Properties window are the same. For more information, see WPF and Silverlight Designer Overview and Silverlight Designer for Visual Studio 2010.
You can bind Silverlight custom controls to data by using the data binding builder. For more information, see Data Binding in the WPF Designer and Binding Silverlight Controls to Data in Visual Studio.
If you author custom design-time experiences for your Silverlight controls, you use the same extensibility API that you use with WPF custom controls. For more information, see WPF Designer Extensibility and WPF and Silverlight Designer Extensibility Samples.