Not so long ago i was having some debates with some of my collegues arround Accessibility issues with SharePoint web sites. Obviously the well known limitations of the v1 of the AKS (Accesibility Kit for Sharepoint) has determined Microsoft, and their new partner HiSoftware to comme up with something really useful. So now is available at https://aks.hisoftware.com/default.aspx. We are in the stage of testing it, especially now that we have planned for some prototypes (read case-studies) that arround the AA of SharePoint sites.
You will also find one brand new control called aRTE (yes you guessed accesibility Rich Text Editor), built by guys from HiSoftware.