A MathML for CSS Profile Has today been edited in place to confirm that it has passed all the ballots and implementation requirements to proceed to full W3C Recommendation status.
The final hurdle is that it has a normative dependency on CSS 2.1 which is currently at Candidate Recommendation stage, so MathML for CSS is blocked at Proposed Recommendation stage until CSS 2.1 reaches Recommendation. Hopefully early next year.
There are apparently several W3C Working drafts similarly blocked by CSS 2.1 (which has been at Candidate Recommendation stage for over a year). Hopefully the CSS Working Group will get the remaining issues resolved and testing reports done this year!