Krzysztof Cwalina and the gang have been working on a tool to make it easier for Framework designers to design, review and maintain highly usable APIs...  You have to check out Framework Design Studio.

We'd love to hear what you think!

Currently the tool is focused on:

• Listing APIs exposed from a managed code assembly
• Comparing APIs in two versions of an assembly
• Reviewing APIs, commenting on API design, and filing review bugs to a defect database (through a configurable plug-in)
• Exporting API review comments to a Microsoft Word document

Adding Review Comments:

Comparing API Versions:

Showing removed and added APIs:

Export to word: