•It’s at
‘Final Call’ draft stage, i.e. it’s not a formal
specification (yet).
•
WAI is the
‘branch’ of W3C that develops accessibility standards guidelines.
In addition to
WAI-ARIA, WAI are also responsible for WCAG (which I’m sure you’ve all at
least heard of), plus some others that you might not have, e.g. ATAG
(authoring tool) & UAAG (user agent).