Feedback requested: application as a landmark role

On today's PFWG call, the group voted to include application as one of  
the ARIA landmark roles. The problem now is incorporation into the spec.

All of the current landmark roles are inherited from the XHTML Role  
Attribute Module [1]. Because application is not one of the inherited  
landmark roles, we'll need to make some changes to the role taxonomy.  
The current proposal is to add an abstract landmark role as a child  
role of region; all of current landmark roles, including application,  
would inherit from the abstract landmark role. The relevant portions  
of the current and proposed taxonomy follow.

Current inheritance model:
	* region
		* banner
		* complementary
		* contentinfo
		* main
		* navigation
		* search
		* other non-landmark child roles of region

Proposed inheritance model:
	* region
		* landmark (abstract role)
			* application
			* banner
			* complementary
			* contentinfo
			* main
			* navigation
			* search
		* other non-landmark child roles of region

1. http://www.w3.org/WAI/PF/aria/#roleattribute_inherits