The WPF Test Tools
release will include tools for testing your WPF applications.
Included in this release:
You may also be interested in the TestApi
library. 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