role=main seems mostly redundant with HTML5 <article>

The landmark role main seems roughly redundant with the first HTML5  
<article> element in a given document. Moreover, Opera for Mobile has  
demonstrated that the main content of a document can be identified  
rather reliably without specific markup.

Since realistically ARIA will be used in text/html, does it make sense  
to introduce stuff that is redundant with HTML5 when implementing  
role=main and implementing exposing the first <article> as the main  
content are about equally easy?

-- 
Henri Sivonen
hsivonen@iki.fi
http://hsivonen.iki.fi/