There is a real opportunity here for evernote and even google. What he needs a personalized wikipedia, a "facebook" of googleable archive of his selected internet content.

If facebook/myspace are the social networks for people's offline life, how about a social network for people's brain in online life.

It is much more than a personal knowledgeabase per se. This may very well be a knowledge graph in google's scale but with personalized context and relativity.