As web authors aren’t watching standards lists, much of the useful practical info about how these standards improve developer ergonomics is lost. Specs boil down the discussions for implementers and APIs but author-facing info isn’t prioritized. A good example: nearly all developers consider it a “trick” that you rev a comment in an appcache manifest in order to indicate the cache needs to be refreshed.
The HTML5 specification’s “web author” mode is a very good starting point for improving the web author view of a specification. (http://developers.whatwg.org)
looks like the feature detection was proposed already: http://www.w3.org/Bugs/Public/show_bug.cgi?id=13853
hixie asked for a web service to ping for each feature and the spec would show results inline.
Too many has changed in the last 5 years, including some standards projects moving to GitHub.
This issue might need some updates in case of re-opening it.