Forum OpenACS Improvement Proposals (TIPs): TIP #115 (IMPLEMENTED): HTML 4.01 Strict
mechanisms for style sheets, scripting, embedding objects, improved support for right to left and mixed direction text, and enhancements to forms for improved accessibility for people with disabilities.
excludes the presentation attributes and elements that W3C expects to phase out as support for style sheets matures.
I think it's a necessary step for the accesibility work that has started with Zen, and also for the upcoming one on theming.
I don't think it will take that long for core (it will for .LRN).
UNED (Adenu group) will do the work.