You can easily tell firefox to use another program (or even service) to subscribe to the feeds. I've got mine going to google reader with them. The icon has been removed from firefox 4 (I'm running the betas). I don't know if they'll put it back in by default from any amount of pleading, BUT surprise surprise, there's an extension that reimplements previous functionality. https://addons.mozilla.org/en-US/firefox/addon/rss-icon/