Great blog post from Lync 2010 Team about accessibility.
Accessibility was an important consideration we put our efforts into during Lync 2010 development. In addition to helping our customers with disabilities, these improvements also bring about broad usability enhancements in the product.
We have made improvements in almost all accessibility areas (keyboard navigation, high dpi, high contrast, shortcut keys, global hotkeys, focus indication etc.). Additionally, we have made sure the initial level of accessibility for all the new scenarios introduced in Lync 2010 are higher compared to past releases (collaboration features for e.g.)
Read the full story at: http://communicatorteam.com/archive/2010/10/06/Accessibility_Features_in_Lync_2010.aspx