Jon Udell's (Personal RSS Aggregators) article discusses the benefits of what I call "citation analysis" - a number of people are referring to this, but all the context of Google. While probably the most famous implementation I think it is quite probable that weblogs themselves will benefit from this analysis to determine "hubs" and "authorities".
Profundis (it no longer works, but the docs are 'interesting') implemented a variation on the algorithm proposed by Jon Klienberg and yielded interesting results. What Profundis showed was the web as communities - and the algorithm would reach a steady state on these communities. What would be interesting is whether weblogs are also "steady state" communities (they should be because they are just web pages) and whether application of the algorithm would enable one to find (by recommendation of the algorithm) the most relevant to oneself of the logs in the community.
Profundis was written a couple of years ago - it appears that Jon Klienberg has some new papers up (or after I was looking) on gossip protocols (whatever they are) and analysis of small worlds - might be interesting to follow up.