Amends the Guardianship and Advocacy Act. Changes references from the federal Developmental Disabilities Services and Facilities Construction Act to the federal Developmental Disabilities Assistance and Bill of Rights Act of 2000. Provides that a majority of members of the Guardianship and Advocacy Commission, excluding vacancies, (instead of 6 members of the Commission) constitute a quorum. In a provision concerning regional authorities making their findings and recommendations public, provides that it shall include in any such public statement any reply made by the State agency, service provider, or other person investigated, if requested by the provider. Amends the Mental Health and Developmental Disabilities Code. Makes changes to the definitions of "guardian" and "mental illness" and adds a definition of "under guardianship". Changes references from the Guardianship and Mental Health Advocacy Commission to the Guardianship and Advocacy Commission.