Here are a couple of services I would like to see.
- Index the web of feeds (just as Google does) but weight the words in the index by recency. Presumably one would still get a Zipf's law distribution of word frequencies. (See, for example, Zipf's Law.)
What would be more interesting than the absolute distribution of word frequencies is the change from day to day. For example, I imagine that marriage has appeared much more frequently during the past couple of weeks than usual. I suspect that its appearance has dropped off since the Senate ended consideration of the FMA.
- I would also like to see a network of references: which blogs refer to which other blogs and other sources. That too probably changes from day to day. If a newspaper breaks an important story, it will probably be linked to quite widely.
More interestingly, a collection of blogs may have a discussion among themselves about a subject. A dynamic network of inter-blog links will show that discussion going on.