The vision: to help our customers write high-quality .NET applications and to drive test code reuse in the tester and dev community. To that end, TestAPI is now live on codeplex. You can check it out here: http://www.codeplex.com/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 

 The library will be updated based on internal needs and on user input.