STR: 1. Open http://developer.mozilla.org/en/docs/Special:Recentchanges 2. Middle-click the feed button in the location bar to open the subscription UI in a new page. Actual results: Nothing happens, as there are multiple feeds, which means you're supposed to left-click the button and select one from the popup menu. Expected results: Either open the popup menu on middle click or just open the subscription UI and let me choose the feed in there. (Maybe pre-select a feed, as some pages just send the same content in Atom and RSS and frankly I just don't care which format the feed is in.)
how about open all feeds in new tabs?
the feed button from urlbar has been removed, and I don't think it's worth to even evaluate adding special middle-click behavior to the toolbar button.
Marco, is there a link you could provide to a bug report or other discussion which resulted in the feed button being removed?
bug 578967, just please avoid commenting in it, mozilla.dev.apps.firefox or mozilla.dev.usability are the right places to discuss.