John Robinson had these here for a long while and I have been using them off and on with a feed reader.
I think the new thing is he is utilizing a new standard that tells a browser the website offers a feed for that page.
Yup. The orange RSS icon appears in the lower right hand corner of the Firefox browser when you come to a page that has RSS Newsfeed capability. If you click on that icon, and you have Thunderbird (the Mozilla email client), it will add that page to your subscription in Thunderbird.