Perhaps this is beyond the scope of what you’re trying to do, but what about auto tagging (select) feeds? Too many feeds don’t provide any, or appropriate tags.
I’d also love to see similar stories grouped or hidden or something. Ideally one curates a set of feeds that compliment each other, but often multiple sites report on the same topic. I’d like newsblur to detect same/similar stories and only show me the one I want. Perhaps the biggest article, or by time, or from a specific source.
Only with newsblur can I follow as much as I’ve always wanted to be able to. It does it’s magic sifting and I only see what i actually want to see. I see both ideas as a natural extension.