From 13 October 2009 UAI TF meeting:
DB: log - role that is a handy way to get a live region
... like a table that is kind of an online chat - rows get added dynamically
... experience is degraded unless use underlying markup
... browser should expose what it would expose if role="log" was not there and add aria-live attribute

CS: maybe this is a strong/native semantic thing - log should not override table
... but if put it on a div, then it should change the role

DB: use of log should be for making something live, not changing the role semantic

CS: need a note - comments column - or footnote - if log is placed on something that has its own mapping, should not change
...if it's placed on something that doesn't have its own mapping, like div, maybe it does have a mapping, still open for discussion
... in all cases, it makes it a live region
... question is why does this even exist?

DB: expose as live attribute - polite but not in the DOM

CS: might make sense to add to DOM
... why do we even need log? can just add aria-live attribute

DB: note that there is a similar HTML 5 element

http://www.w3.org/2009/10/13-aapi-minutes.html