Micrsoft WPF Testing team has just released the TestApi v0.5, which includes a few new additions and updates including:

• Combinatorial Variation Generation API - added supports for generics and declarative models (attribute-based models)
• Fault Injection API - for .NET 4.0 binaries
• Text String Generation API - added the support for string generation for multiple UnicodeRanges

The new release can be downloaded here.  Please send your feedback and share your thoughts for APIs that you'd like to see included in future releases.