The current debate about edge cases, as regards RSS feeds, is missing a very important point. With today's model of feed consumption - subscription and aggregation - it is true to say that someone, like me, who funnels hundreds of feeds into his attention space each day, is indeed an edge case. But with tomorrow's model of feed sampling - glancing and grazing we'll all be edge cases.
When you walk down the street do you subscribe to the thousands of sensory feeds in the information ether? Not at all. You're scanning, skimming, sampling, glancing.. As you pass a group of people on the pavement you briefly graze their converation. Each one is transmitting an auditory feed, a podcast you might say. The nearest to you comes into earshot first and then a second. Your Reading List (dynamic OPML file) now contains two feeds. Then a third voice comes into focus. And finally the fourth. As you pass by the first voice wanes and disappears from your Reading List. And eventually they all fade.
Do 'normal' people close off their senses to the millions of things that are happening on the street? Of course not. But the reason they're not overloaded by information is because the human being has developed a very useful sensory filter. She doesn't subscribe to anything! It's not that she has to make a conscious effort to unsubsribe from the conversation as she walks by; she merely stops sampling it. Even before its gone out of earshot.
In real life we don't wed ourselves to information flows. It's not a case of 'til death do us part'. RSS aggregators allowed us to divorce from the webpage but we're still married to the feed. Feed Grazers will remove us by another level of commitment from the information flows in the digital ether. Information promiscuity will be the order of the day ;-)