ARIA: splitter pane and/or grip?

Hi all,

I noticed the absence of a split pane role in the ARIA docs. I'm not 
sure we need one, but was just curious if it had been left out on purpose?

What about a splitter-grip for the widget that allows pane co-resizing? 
Again, I'm not sure if we need this, or if we can capture the semantics 
in some other way.

cheers,
David