There's already quite a lot that you can do with Learning Gateway, and explicitly the SharePoint components, to increase accessibility to users, across devices. And this news item I read promises more:

Shared-source software kit will advance the accessibility of SharePoint-based solutions for people with disabilities

July 31, 2007 — HiSoftware , a leading provider of software, services and managed operation solutions that monitor and optimize Web content governance, quality and regulatory compliance, today announced an agreement with Microsoft to develop the Accessibility Kit for Microsoft Office SharePoint Server (MOSS) 2007. The kit will provide templates, master pages, controls and Web parts along with technical documentation to advance MOSS accessibility for people with disabilities. All of the source code will be provided via the Microsoft Permissive License and will be available on CodePlex (www.codeplex.com) later this year for customers and other Microsoft partners to download, reuse and extend.

The Accessibility Kit for Office SharePoint Server will include site templates, Web parts, documentation, instruction and tutorials enabling partners and customers to develop Web sites that conform to the guidelines set out in the W3C’s Web Content Accessibility Guidelines (WCAG). The solution will also provide accessibility updates for Office SharePoint Server templates and Web parts for Web publishing, corporate intranet, team and project collaboration sites and more. This allows users to create a site and replace “out-of-the-box” MOSS components with accessibility kit templates, reusable Web content and Web parts.

As part of the testing for the kit, HiSoftware will work with Microsoft, key stakeholders and early adopters to maximize value and functionality, including organizations in the UK and worldwide.

Accessibility Community for Office SharePoint Server
As part of this initiative HiSoftware will provide an extensible platform with an open API and SDK, on which other Microsoft partners can build, collaborate and extend. HiSoftware will lead a partner and customer community to share thoughts, solutions and strategies for enhancing usability and accessibility across MOSS deployments.

There aren't any more details available yet, other than what's in the HiSoftware press release, but look out for the first releases in the autumn! And when I know more, I'll post it here.