RSS feeds offer a great way to quickly check news and updates from different sites without visiting them all. RSS support is new to IE 7, and upgraded in Firefox 2.
In IE, if you browse a page with an associated feed, an icon to the right of the tabs will light up. Click it, and you'll see the latest headlines from that feed along with an option to subscribe. Once you subscribe, you can check it via the feeds button in the new Favorites Center, where you'll also find your browsing history. However, you have no way to quickly preview the feed's contents without opening the feed's rendered page in IE, which somewhat defeats the purpose--you may as well visit the regular site. Microsoft says that it deliberately designed IE's feed support to be bare-bones because it is meant as a platform for future RSS reader applications.
Using Firefox 1.5's Live Bookmarks, you can bookmark a feed and then preview all its headlines at once. If you click a headline, you go to that story on the relevant site--but if you click a link that opens the feed itself, you see only Web-code gibberish. Firefox 2 makes the raw feed understandable, and offers a range of new subscription options. For example, you can now add a feed to a personal Bloglines, Google Reader, or My Yahoo page, or to a stand-alone RSS reader, though it may not work with all readers.