Recently I published the RichTextBox.Xaml Builder standalone tool. Now I have ported this WPF application to an Expression Blend 4 Add-In and gave it to the community.
The features are similar to the standalone tool, but you can now use the functionality of converting rich text to xml with a xml document structure which is compatible to xaml directly in Expression Blend 4.
For more information read this short blog post. Unfortunately I am still having some technical problems with my english blog, so please use Bing Translator to follow the german text on my Blog.