I'm required by law (Section 508) to build accessible web sites at my day job. It's much easier to make Section 508 compliant websites without JS. Then we put the icing on the cake to satisfy the other 98% of our users.
It seems to me that a lot of expensive accessibility software copes well with computing circa 1998. But then it hit a wall. Most of the advocacy and lobbying around this issue seems to focus on forcing most developers to adapt to the limitations of this accessibility software, rather than pressuring accessibility software vendors to provide software which (a) delivers innovation and utilizes advanced technology, as you'd expect in 2010 and (b) deals with common patterns in modern software development.
Now imagine I'm surfing as a blind user, and I follow a link from HN, and my screen reader starts reading the page, only to be interrupted by a "take this survey" modal DIV. After a couple of times I'm turning off the JS, cos that's really annoying.
The people who make my zoom software make OSX (it's built into the operating system and it works amazingly well for me except for applications which fire events when I hover.
Following the principles of UJS and web standards makes it infinitely easier, in my experience, to develop web sites that work with screen readers and still use that advanced technology that everyone's gaga over. But if you can't write JS easily that works across multiple browsers, how do you ever expect assistive technology to be able to interpret it correctly? :)
It'd be nice if Apple could turn around and kill the hover in Safari when somebody's using the zoom feature. It'd be even nicer if you could toggle this on and off right now (right Apple button, maybe?) because mouse hovering in the zoom application is obviously _not_ necessarily the same user action as mouse hovering without the zoom app.
"Take this survey" DIVs destroy usability for everybody :(
I am open to suggestions :).