The structured logging RFC [0] will be up for discussion again next Wednesday [1]. There is a strawman implementation in gerrit [2] that is likely to be the focus of discussion unless there are other issues that the reviewers find more pressing.
At this point the most controversial aspect of my proposed implementation seems to be importing third-party libraries into mw-core and/or the use of composer to manage that activity. I would welcome discussion of alternatives or consensus that this is a reasonable approach for the immediate future that should be revisited if and when a better idea is found for the general problem.
[0]: https://www.mediawiki.org/wiki/Requests_for_comment/Structured_logging [1]: https://www.mediawiki.org/wiki/Architecture_meetings/RFC_review_2014-03-19 [2]: https://gerrit.wikimedia.org/r/#/c/112699/
Bryan