One major problem with the internet is its homogeneity. Not the overall web, just what you look at. Most of your web traffic probably pulls through the same corridors. I have a steady stream of blogs I read regularly, a twitter collection of commentors, and whatever comes through my inbox. Blogs, tweeps, and Inbox were all my creations and because so, customized by me to only receive the news I want. My bias isn't towards FOX or HuffPost but both, and this uniformity probably makes me more informed than either single subscriber.
I know that most men — not only those considered clever, but even those who are very clever and capable of understanding most difficult scientific, mathematical, or philosophic, problems — can seldom discern even the simplest and most obvious truth if it be such as obliges them to admit the falsity of conclusions they have formed, perhaps with much difficulty — conclusions of which they are proud, which they have taught to others, and on which they have built their lives. Tolstoy
Ironically the difficulty of good algorithms simplify rather than confound this problem. Google is good for finding four plus three but not so good if you are just telling it to look for numbers that produce seven. Netflix has invested more than anyone else to create a good recommendation engine for movies and I never err with it. Rating Crash and Million Dollar Baby as good movies won't get more good movies, just popular ones.
The Daring Fireball RSS feed was sponsored by XYDO, which claims to "learn what you like so you only see what's interesting to you from across the web". Even if they could succeed I'm not sure they'd want to.