WPF MVVM XAML design – VS 2010 XAML designer – Design time data-Collection of common programming errors

First of all, give the designers Microsoft Expression Blend, not Visual Studio. That is what it is meant for.

Second of all, in Blend, designers can create fictive data for displaying, however, since the data types (the view models) are not defined yet, they can edit the views and data templates without data.

Also, try searching in Google for: expression blend sample data
– you will receive a lot of relevant results.