The feature being pulled is with reference to the Aurora (not the current stable). I'm not sure that "html/css/js or whatever spec" would be affected. The folks who are into theme-ing the "chrome" and writing extensions seem to be running up the wall Anyway, you have practical knowledge of whether you've actually be affected while designing web pages.
I like it for Firefox. (Can't really comment on Chrome.) Reasons: 1. Mozilla gets more feedback from the beta, aurora, nightly users. This improves the quality of the new features. And contrary to other claims, most addons work flawlessly - and I'm using a lot of them. 2. You might not always like those new features, but fortunately FF is still very configurable. In most cases you can go back to the old behavior. 3. Improvements/new features are implemented faster. In light of the increased competition by other browsers, Mozilla didn't really have a choice. And what numbers they are using for those new versions is really irrelevant. That's why I think that most of the objections against rapid release are only a tempest in a teacup.
If you look at the release notes there are backouts between beta and stable, but usually very minor, but there is atleast one per release, don't think its a realworld problem usually though.
I think things are simpler for Chrome because the extensions don't have as much access to the innards of the browser and because Chrome is mostly adding rather than subtracting.
Chrome's subtracting in terms of extensions. The new Content Security Policy will break things for developers. But it doesn't matter, they announced it months in advance. I also think that many Firefox addons worked for years because the browser barely changed. The developers could basically leave their projects for months at a time without updates. Chrome developers from day 1 knew the extension release cycle.
