Perfect example of something that most people will think of as "not necessary", but a whole industry will understand as close to, if not outright, a deal-breaker!
It would be really cool to have some kind of open source community that developed these kinds of "usage specific" plugins across multiple open-source projects, to kind of patch in that functionality where it's missing. Some people to work on ever-evolving interfaces for the supported applications, and then some other people to write plugins that provided these features, progressively enhanced, based on those interfaces.
It would be a gargantuan effort, though, and you would just end up with a plugin soup without careful moderation (even more effort; and easy to go awry!) so c'est la vie!
