Specify what ARIA information may be used by mainstream user agents to create UI

Re: http://www.w3.org/WAI/PF/aria/

It's currently very unclear when ARIA may be used by mainstream user 
agents to create UI.

Some evidence of confusion:

http://groups.google.com/group/free-aria/msg/1826be8e0919776c

http://lists.w3.org/Archives/Public/public-html/2009Sep/0120.html

http://lists.w3.org/Archives/Public/public-html/2009Sep/0144.html

http://lists.w3.org/Archives/Public/public-html/2009Sep/0157.html

http://lists.w3.org/Archives/Public/public-html/2009Sep/0212.html

There's a real tension between ARIA as a side-effect-free method for 
divitis Ajax frameworks to support AT or bridge to HTML5, and ARIA as a 
source of semantics for markup languages like SVG. I believe providing 
normative language around this would clear up that tension.

Please specify in normative language in the WAI-ARIA specification what 
ARIA information:

1. MUST only be exposed to APIs (DOM, CSSOM, accessibility APIs) for use 
by assistive technology that harvests information via such APIs.
2. MAY/SHOULD/MUST be used by *any* user agent to provide UI (for 
example, providing keyboard navigation through ARIA landmarks, or 
keyboard operability of an ARIA checkbox).

If necessary, require host languages to define this for conformance.

--
Benjamin Hawkes-Lewis