I've been noticing the use of a standard new icon for feeds lately on a lot of newer sites, and I immediately recognized it because I use FireFox and that's what pops into the address bar if a web page has a feed associated with it. My immediate reaction to seeing the icon on those sites was "Hey, that's nice, I like that." Which, I have to say, is pretty opposite of just about every other feed icon I've ever seen, including the orange xml, rss, coffee cup and other variations. I honestly thought it was sort of a coincidence, but it turns out that it's actually more of a movement started back in December when Microsoft decided to adopt FireFox's feed icon in IE. Thus a standard was born. Awesome.
Check out Feed Icons - it has all the image files you need to add it to your site.
There's a lot's of nice things to like about this new icon: First, the size and color are not specified, so you can incorporate it into your page design more naturally (though I think orange is generally best). There's no text in the image, so it's neither geeky, nor political (RSS vs. XML, Atom, Feed, etc.). And finally, it's already supported by the two major browsers (FF and IE), so it's got some momentum there as well. I'm sold. Once some major portals like Yahoo!/GOOG/AOL/MSN support it, it'll be all over, and I think life will be a bit better for a lot of users out there. (Check out Yahoo! Big List of Feeds we have, and how we don't even use the same one across our own properties.)
Update: I added some XSL magic to my feed as well, using the new icon and a link to my CSS. I was going to just link to it here, but since I did the same to Mobile Monday's feed which is using the default Kubrick style, I just zipped up the XSL and image files I added and the wp-rss2.php I changed so you can just slap it on your WP site if you use it as well. Download it here.