Identifying the supernodes
Based on the top 100 listed at scripting.com's community feedlist, one third of the news I read is read by the other 125 people. This list is generated from the top 100 feeds out of everyone who's uploaded OPML; you can do so, too. Just create an account and you're set to go.
With this data, you could identify what blogs the top 100 most-read bloggers *aren't* reading, read them, and feed them interesting tidbits that they might not see otherwise. You could customize your blogging for any audience. You could target only B-list bloggers. You could create a directed network graph of who's reading who, find out who isn't reading who, and fill in the gaps.
If this new service provided an aggregate dataset, I could teach people to become supernodes. Unfortunately, the aggregate dataset being collected by this service is not available for download. I suggest contacting Dave and asking him to please republish the aggregated information in XML form.