What I would love to see is a method for tracking or indexing reputation of a site by some automatic method. As it is, I can kind of infer how reliable a site is based on the language I see, and the types of headlines, and whether others have told me it's reputable. I would love to see that automated somehow. News aggregators try to solve this via upvotes, downvotes, or flags, but there are plenty of reasons to upvote that have nothing to do with reliability per se, and trying to use multiple upvoting buttons seems silly, because at the end of the day rank is a one-dimensional property, so you'll have to combine "funny", "reliable", "interesting" into some single number.
It's a "hard problem" but since the value of information depends so heavily on its accuracy, solving it would appear to be very lucrative and valuable to a society in which the quantity of available information grows by leaps and bounds each year. Google seems to have solved "relevance" and I would love to see someone solve reliability.