This is just a quick plug for a new CodePlex project – TestApi

TestApi is an experimental library of test and utility APIs that enables developers and testers to test WPF applications, Windows Forms applications, .NET Framework applications, and Win32 applications. TestApi provides a set of simple, documented, componentized, and layered test APIs, which complement the WPF Application Quality Guide and the materials available on the WPF Testing blog

Worth checking out.