While this is a lengthy document, and a good read for the accessibility community, the main point of contention I have with OOXML is it needs an accessibility review by industry as we have done with ODF 1.0. That review resulted in a new ODF 1.1 specification that not only addresses accessibility but also raises the bar over other standards. After all, access to office documents is what we call a "high impact" use case for people with disabilities. It is almost as important as web and email access. A look at the ATRC white paper shows what always happens when you do an accessibility assessment - you drum up numerous problems with the technology or specification in question. Why? - because people with disabilities need to have access to all the features of subject in question. So, how does this apply to this document?
As ATRC highlights, there are numerous parts of the specification that are ill-defined and refer to proprietary behaviors as in section 3.4. What is autoSpaceLikeWord95 and useWord97LineBreakRules mean? Imagine yourself being a non-Microsoft office application, on Windows, MacOSX, or Linux, and you wanted to support accessible access to text through the platform accessibility API. How would you do it? This is no different than an office application needing to render the content. I would also contend that an accessibility review could not be completed until these holes in the specification were filled.
OOXML is now a published specification (ECMA-376) submitted to the International Standard Organization's JTC-1 committee for fast-track (get it out fast no matter what state it is in apparently) consideration of its adoption as an international standard. If this gets approved by ISO you have to question the ISO standards acceptance procedures, given that only one company can implement the standard, and its commitment to accessibility - which in the past has been exemplary. I do hope that ISO lives up to its reputation and demands an international accessibility review and that Microsoft be required to address the findings. If not, the creation of an open standard will have had no impact on the status quo and people with disabilities will continue to be left out in access to other office applications and operating system platforms - and accessibility gaps will still exist in Microsoft Office. To the best of my knowledge blind users still don't have access to MS Office on the Mac.