What if Safari detected RSS feeds?

Here's an idea for Safari: Many web sites/pages now offer an RSS feed equivalent of their contents, not unlike this weblog! As RSS is getting more and more popular, it would be cool if Safari would detect the presence of an RSS feed (through the <link rel="alternate" type="application/rss+xml" ... > tag) and activate a UI element on its toolbar that the user could use to drag to their favorite news reading program .... Say, NetNewsWire.

mockup of Safari toolbar with an RSS item