Sara Ford provided a link to the 2011-03-17 Microsoft announcement of Free Accessibility Tools and Training for Developers. The Accessibility Tools & Training and the Accessibility Resource Guide are located at a comprehensive Accessibility Overview page. There is extensive material here, and the specific materials are just one of the links, one for a downloadable CD (410MB ISO image), the first of the Tools for Business, Organizations, and Governments.
This appears to be an overwhelming abundance. It will certainly figure in what there might be available at the C/C++ level, although the connection of UI Automation with Windows Presentation Foundation may not fit my ideas for simple cases.
There is clearly a great deal that a Microsoft-oriented developer can learn here. I can start with that. This is certainly a step above the fussing around about accessibility provisions in markup languages. I’m not sure about the open-sourced add-ins for Microsoft Office. Those seem to be at a different level. All is welcome.