We've noted before that we don't use RSS to keep track of our favorite sites. We prefer blo.gs for two reasons:
On the other hand, we syndicate this site via RSS and Atom, write about RSS, and support its growth. We do this because we believe its potential stretches beyond a weblog updates service (and, in all fairness, because more than four times as many of our visitors access our recent content via aggregators than via browsers). Yahoo's new personalized RSS feeds, built on keywords you provide, are evidence of this potential. Tracking specific names, companies, topics, and so on, is far more useful than simple notification that a site has updated. As Simon Willison pointed out, Yahoo isn't the first to do this, but they're certainly the biggest. Time to scrape the dust off our aggregator.