Sorry if I am missing something obvious here, but why wouldn't you want to use the ARIA role directly on an existing element:
I typically use a section with a "main" role to identify and style my main content:


<section role="main"></section>


section[role=main] {


David Corvoysier

Le 09/09/2012 21:24, Steve Faulkner a écrit :
There has been continued discussion [1] in other fora on the addition
of an element that identifies the main content of a web page, the idea
has been around for a long time.

This element would formalise common the common practice [2] of using
an id value such as "content" or "main" (typically on a div) to
identify a container element for the main content area of a document
or application. It would also provide an element that is a  HTML
version of the ARIA role=main.

I have put together a draft definition of such an element for
consideration and discussion:

[1] http://lists.w3.org/Archives/Public/public-whatwg-archive/2012Sep/0008.html

>From publically reported studies  of id values used in HTML content,
the use of the strings "content" and "main" are common practice.
[2] http://triin.net/2006/06/12/CSS#figure-34,