ARIA roles added to the a element should be conforming in HTML5.

Currently the a element is defined in the HTML5 specification as an element
that cannot have its native role overriden by ARIA roles [1]

This is contrary to use in the wild as it has been overriden by the addition
of a number of roles in popular javascript UI libraries.

Examples:
button
http://jqueryui.com/demos/dialog/
http://developer.yahoo.com/yui/examples/carousel/carousel-ariaplugin_source.html
tab
http://developer.yahoo.com/yui/examples/tabview/tabview-ariaplugin_clean.html
menutiem
http://developer.yahoo.com/yui/examples/menu/menuwaiaria_source.html



It is important to understand that it is not ARIA that is making the link
into a button, its the developers use of javascript, event handlers and CSS
that is making it look and act like a button or tab or menutiem. The
addition of ARIA is merely providing the information that other users get by
default. So making the addition of an ARIA role non conforming, to an
element that has been designed to act and look like something other than its
native role, is not the appropriate repsonse.

The reasons for creating ARIA centered around the inability of the HTML
specification to address how author would create content. In fact, with the
exception of forms, it was assumed that HTML would only be used for
documents. Clearly, that was a miscalculation.

It is essential that authors be given the tools to produce accessible
applications. The perception, by some, is that ARIA is meant to circumvent
the semantics of the host language, but rather it is the author that is
circumventing the host language to create UI controls that satisfy their
needs. WAI-ARIA simply provides the semantics to make them interoperabile
with assistive technologies.


NOTE: there are 60+ more elements that have prohibitions placed on the
addition of ARIA roles, so this is but one example of what has to be
reviewed and bugs entered for in the HTML WG bug tracker where necessary. I
suggest this is one of the tasks that the accessibility taskforce should
undertake.


[1]
http://dev.w3.org/html5/spec/embedded-content-0.html#annotations-for-assistive-technology-products-aria

-- 
with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html