One of the new additions in Expression Blend 4 is the Silverlight Databound Application Project template. I use that often when starting a new MVVM project. The template creates View and ViewModel folders and provides a good starting point for Model-View-ViewModel applications. The only downside is that this template is only available in Expression Blend and not in Visual Studio 2010.
I’ve exported the project to a Visual Studio template to be able to use it in VS2010 too.
The template can be downloaded here.
Just place the .zip in ??\Documents\Visual Studio 2010\Templates\ProjectTemplates\Visual C#\Silverlight
Do not extract. It should work in VS2010 now.