Live Bookmarks are a new feature in the FireFox 1.0 candidate release. It basically lets you view an RSS feed is a folder of bookmarks, updating as the site updates. Very clever idea, decent implementation too.
However, to claim it is a browser innovation is wrong. Internet Explorer has been doing the exact same thing with CDF feeds for an age. As long as the MIME type is being served correctly, clicking on a link to a CDF file adds it as a live folder in bookmarks.
Clever, but now new.