RSS stands for Really Simply Syndicatation, but before it can breakthrough big-time to the public, it's still missing a really simple method to locate feeds.
This doesn't mean a decent RSS search engine. It means a centralized, perhaps regulated, method for recommending and subscribing to feeds.
There are two barriers to brain-dead simplicity.
1. It must be easy to find relevant feeds. Too much hunt and peck is involved. The reason My.Yahoo and iTunes have been successful is that they centralize a lot of the discovery, they make it easy to find stuff you might be interested in. But not easy enough to qualify for brain-dead simplicity.
2. Subscription has to be centralized..
Check out the full post by Dave Winer titled, How RSS can bust through.