The Office Platform Team released two new Microsoft Office 2010 Accessibility Add-ins on March 17th. While comparatively small add-ins, they enable big things! Try them yourself by downloading via the below links.
The Subtitling Add-in for Microsoft PowerPoint (STAMP)helps Microsoft PowerPoint 2010 users add closed captions to the video and audio files included in their presentations, which boosts their impact for those with hearing disabilities. This also enables video and audio in PowerPoint to be localized in different languages.
The DAISY Consortium, Save as DAISY for Office 2010 helps Microsoft Word users convert Word Open XML files to the Digital Accessible Information System (DAISY) format, which powers digital talking books and compatible software & braille readers for this with print disabilities. This version now supports Office 2003, 2007 and 2010.
To get a full picture of all the Office 2010 Accessibility features, you can do here