Disclaimer: this started essentially as note-to-self listing a few interesting projects to spare me another internet search session.
Interestingly a huge amount of websites produce this kind of feeds (most blogs obviously but also sites like twitter[en]) and from this point of view the RSS format is quite lively.
But on the consumer side, I’m pretty disappointed with the “offer” in terms of RSS readers. Over the time I’ve tested several well-known desktop readers (liferea, rssowl, thunderbird…) and most of then ended up synchronizing with Google Reader. This one has consequently come to be my main newsreader and it appears to me as clearly dominating the world of internet based newsreader. However such a predominance is not that much a good sign1.