A google search for "firefox attributeStyleMap" yielded little info about the state of this, but one of the results was a specific commit at a mercurial repository at Mozilla[1], and it seems to be a patch to add this. So perhaps it's much closer than you think?

Edit: Actually, I wasn't paying too much attention to the commit initially. Apparently it's not implementing attributeStyleMap, it's using it as if it exists, so I suppose it's already implemented in this branch, or this is a test in anticipation of it.

1: https://hg.mozilla.org/mozilla-central/changeset/f4e33c42faa...

No, you've linked a merge commit, which is merging a bunch of stuff.

One of the things it merges is BZ # 1442425 which is landing a newer version of the W3C's set of web platform tests, seen here testing the Typed OM feature you are interested in:

https://github.com/w3c/web-platform-tests/tree/master/css/cs...

So, this actually tells you nothing about whether Firefox is interested in implementing this or plans to do so.

Hmm, so what is the status of this W3C draft[1] (which they say specifically does not imply endorsement), if the W3C is putting a test for it in one of their test suites? Or do Chrome/Chrome devs get commit bits? Or maybe one of the purposes of this is to serve as a way for browsers to coordinate on implementations even before it's become a standard? (It's obviously a way to coordinate on things that are a standard).

1: https://www.w3.org/TR/css-typed-om-1/

It is a standard, what do you want browsers to do, all hold off until they have all implemented?

Not quite, but new and unproven features are supposed to be hidden behind a runtime flag to prevent a hot mess like what was caused with CSS/JS vendor prefixes.

The Blink team are getting better at this, but they still really need to put their feet on the brakes a little more, and wait until there are at least two implementations ready before flipping their own switch to enable the feature for all of their users.

With two reasonably complete (and independent) implementations it's far more likely that the standard is engine-neutral, and not lacking in crucial detail. The web platform tests will also have been put to the tests to ensure that they have decent coverage. On top of that, the feature can be considered to have been vetted to ensure that it isn't really just being shoved on the web to meet Google's business needs, but rather in the interests of a broader set of people. These things can easily slip if pushed too quickly, even if others are generally supportive of the general idea of the feature.

ie6-style attack on standards was google plan with chrome from day one. their internal moto was something like "reshaping the future" or sone other facist theme I dont recall now