Around quarter one 2008 I gave up on editing the CSSOM specification in favor of investing more time in XMLHttpRequest, XMLHttpRequest Level 2, Cross-Origin Resource Sharing, CSSOM View Module (something I decided to split out from CSSOM), and of course HTML5 (more in a reviewing it and dealing with politics way, not much editing). Nowadays most of these are more or less finished or are awaiting work to be done by others so this Monday I started editing the CSSOM specification again. So far I have done this:
Default-Style header (turned out to be very easy after all the groundwork was done).
MediaList object works now media queries are present and removed an annoying exception while I was at it (I have some hope I can persuade implementors into following this).
xml-stylesheet processing instruction works for styling languages.
Link header works when the link relation type is stylesheet.
Next is figuring the CSS API out in detail. I wonder how far I will get this time around.