The most significant thing is that Section 508 is under revision. (Section 508 is a federal law requiring accessibility on government websites.) Obviously, full fledged use of AJAX requires tool support for notification of events and the like.
But what about smaller uses of AJAX? One would think that using AJAX to update the values on a pull down below the a pull down the user has changed shouldn't be a big deal for accessibility. After all, the user hasn't gotten to that part of the page yet. It's still linear on the screen. Unfortunately, tool support isn't quite there. But it is closer than it was a year ago.
So my actual question: has anyone tried creating anything using AJAX that is accessible to blind users or does anyone have any thoughts on this.
(I actually had more of a question when I started typing. I learned some - as evidenced by the links - as I was researching to ask the question.)