Categories and metacontent. A great way to increase the quality of flow is self-categorization of content by authors. Keyword searches are fine, but they often miss items that are on topic but don't contain the keyword. Radio has the ability to enable authors to attach articles to categories and create category specific Weblogs. Unfortunately, there isn't a single categorization system available for people to use.
I tried to develop a system of self-categorized content for a research system I built at my last job. The idea was to have analysts publish Weblogs and categorize the entries based on a corporate corpus of metacontent. Customers would have the option of subscribing to the specific category flows that pertained to them. Although I didn't get it finished while there, the idea would be very easy to implement using either Manila and Radio or Radio by itself.
The same idea could apply to news organizations. Weblogs with self categorization would vastly improve the reading experience. It is also a more elegant solution that blunt tools like Moreover.
With Weblogs it is almost a necessity. A personal Weblog is often a mishmash of personal activities, random thoughts, timely links, and great analysis on a variety of topics. There are very few sites I am willing to read in their entirety. An ability to filter news from a large variety of sites into a multiple streams of relevant topics would help improve my productivity as a reader. I would still visit and read the entire Weblogs of people I know, but would rely on the category streams to cover the rest. [John Robb's Radio Weblog]