I've actually been wanting to do this, but I don't personally know a lot of good sources that still use RSS. Would love to see your feed list.
Tech: Hacker News, Tech Crunch, The Verge.
Music: Pitchfork.
MMA: MMA Fighting, Bloody Elbow.
Plants: Epic Gardening and Indoor Gardening, with plans to add some carnivorous plant forums.
Still looking for more stuff. It honestly feels strangely better absorbing without commenting.