W3C roadmap for accessible RIAs

Rich Internet Application (RIA) formats, such as Ajax, Flex, OpenLazslo, XAML, and so on, are all the rage on the Web these days, but sometimes the tradeoff involved in moving from a clunky-feeling page-at-a-time forms-driven web interface model to the more snappy thick-client feel of RIAs is a loss in accessibility (as well as issues like breaking the back button and, as we saw with frames back in the day, the difficulty of bookmarking specific states in the middle of an interaction).
Now it looks like the W3C is taking the bull by the horns: W3C Announces Roadmap for Accessible Rich Internet Applications (WAI-ARIA). Here’s an excerpt from the announcement:

Dynamic Web Content Currently Excludes Many Users: Assistive technologies, including screen readers, speech dictation software, and on-screen keyboards help make the Web accessible to people with disabilities. To accomplish this, these tools require information about the semantics of specific portions of a document in order to present those portions in an accessible form. For example, to provide reliable access to a form element, a tool must also be able to recognize the state of that element (for example, whether it is checked, disabled, focused, collapsed, or hidden).
Web sites are increasingly delivering applications with capabilities comparable to locally-installed software. These rich Internet applications make heavy use of scripting, and developers often improvise hybrids of existing technologies, including AJAX, DHTML, JavaScript, and SVG. These applications do not always provide the semantics needed to support these technologies. People with disabilities are therefore at risk of being left out of this new world of information.