I think that this is another important point. Universal Design, Design for all. Asistive Tecnology. Why not in games too?
I see many thing about software, but not to many about controler design.
Accesibility has importance in adaptative software and options (subtitles for deaf persons)
Audio Games for blind for example.
And also importance in adaptative asn alternative controlers.
Childrens with disabilities also have the right of use new technologies for learning.
Game Accesiblity is also Serious Gaming. Isn´t it?
When a person with physical and cognitive disabilities gets to play a game, for example a oneswitch game http://www.oneswitch.org.uk/ it becomes a terapeutic action, it is a Game for Health, a Game for Learning...