Context based rule interface
With 500+ rulesets in the development branch, it's no longer practical to expect the user to look through all of them, even with a search function.
What we need is a context-based rule interface that lives in the bookmarks toolbar (or status bar, though that's going away) like the ones used by AdBlock Plus, NoScript and Request Policy. Right clicking on this object would give you the ability to enable or disable any rulesets that apply to the document (or parts of it).
This UI could have several visual states:
Enabled. HTTPS Everywhere is fully operational in this page
Disabled. You have HTTPS-E rulesets that are applicable to this page (or 3rd party content within it) but they are not enabled.
Partially enabled. Parts of this page are secured by HTTPS-E
Partially enabled and partially disabled.
Or we could simplify it down a bit further.